This free plugin seems to be exactly for what you want, and is up to date: https://wordpress.org/plugins/multiple-domain-mapping-on-single-site/
You will need to point the DNS A record of the second domain to the same IP as the main one. There are more instructions in the FAQ section of the page I linked.
This is NOT for a multisite. It is for a single WordPress installation with multiple domains.
Related Posts:
- How to let a single post have its own domain name
- One WordPress install for main site at domain.com and blog at blog.domain.com?
- Different Domains in Multisite Setup
- How to use WordPress Multisite With Different Domain Names?
- Can we use one WordPress installation for multiple databases, domains and content directories
- Anyone figured out how to use WordPress MultiSite with Domain Mapping & SSL?
- How to use alias domain for multisite installation?
- .maintenance and maintenance.php also in multisite install?
- How To Provide Sub-Blogs Their Own Domain Names?
- global menus made from master site’s custom menus wpmu network
- Can You Export Theme Settings From WordPress Multisite?
- WordPress Multi Site Best Practice
- Localization For Two Different Regions/Domains with the Same Language
- Changing Multisite URL after the subsite has been in use
- How to run a test WordPressMu to WordPress3 update?
- Suggestions for WPMU Migration (advanced)
- WordPress Network Feature
- How do I use different domain for subdomains in WP Multisite?
- Subdomain and subdirectories together in one installation
- Multi-Site Plugin Activated (Not Network-Activated), What Happens?
- Custom column under All Users (multisite network admin)?
- Syncing Avatars across multisite
- WordPress multisite with multiple parent domains
- Why would switch_to_blog stop working?
- WP Multisite – domain mapping to domain.com and separate site to domain.com/help
- Multiple sites/domains with content all managed by single installation of WordPress
- Override database config for WordPress multiblog
- How to insert a sitemap within a subsite when using WordPress multisite
- Add custom user profile field to default WordPress MultiSite registration form
- Turn off redirect to canonical domain (or host website on any hostname)
- How to host blog on separate domain from main site
- WordPress Multisite domain mapping with different IPs
- WordPress Multisite Strange Redirect on Primary Site
- What changes we need to make to a theme so it can be installed as a MU Theme?
- Multi Site installation inside a sub domain inside a sub directory
- Showcase elementor templates
- Create custom dashboard for Multisite admins
- How can I create a second multisite network in a subdirectory?
- Link structure, WordPress IIS
- Manage multiple domains from one backend
- Static admin page for all multisite users
- 1 WordPress installation with 2 pages: every page gets a separate domain
- How to host 2 subdomains as lookalike destinations under one master domain?
- What is the best way to move a single site from one MS installation to another? [duplicate]
- Multi-site User Sessions
- Install multisite wordpress on a subdomain and map to top level domains
- What happens to the mu-plugins folder when you upgrade to WordPress 3?
- In WordPress 3.x, I can’t access posts from all blogs in the network
- I w’d like to know If there are simple solutions to integrate other CMSs to wordpress
- Multisite – One Site with multiple URLs
- WordPress broken after domain name change
- Multisite on single wordpress
- Add the site’s name as prefix when adding new users? Multisite
- Open “Visit site” in a new window?
- Allow multisite admins only to create users with one specific user role?
- Prevent Multisite from creating sample page, sample post and sample comments
- How to have multiple WordPress Menus
- Folder structure when using multiple domains with WordPress
- Create new network instance, import old single installs AND keep the urls?
- How to do multi site setup
- How to replace blog page url with subdomain at all places, even in xml sitemap?
- How can I resolve a .htaccess internal server error setting up a WordPress multisite?
- how or where wordress collect unlogged user session
- Global theme customization multisite
- Multisite with subdirectories, and a WordPress installation in a custom folder
- website is not loading home page (moving from one server to another server)
- Serve theme and plugins assets from correct domain on multi-domain multisite
- Is MultiSite the Correct Solution for a Corporate Site with Searchable Regions?
- How should I design subcategory login site?
- How to have differents sites share the same tables of DB?
- Add button to My Sites dashboard page (multisite)?
- Create page when a new site in multisite network is created?
- Get site ID from attachment url?
- new WPMS site not working / Q setting up new site/subdomain
- Multi-site customization
- Multisite redirect loop for a single www domain
- title tag function
- Multisite subdomain-site redirects to primary site
- WordPress 3.1 update has reversed my blog posts
- WordPress Command Question
- getting a 404 page for all pages except home. possibly permalinks
- Different profile page by role
- kitchen sink not working
- WordPress menu: How to make www.link.com/#name never contain current_page_item class?
- Troubles about insering a POST with a SQL query, post_status
- Any Good WordPress Client Like Live Writer To Create Static Pages
- WordPress homepage hangs in IE browsers
- Customizing 1 theme for multiple blogs in a multisite setup
- WordPress pagination with custom post type?
- How to retain visual breadcrumbs w/ tricky URL structure? Custom post template?
- 2.9 to 3.0: Pros and cons of upgrading?
- How do I create a Custom Post Box that Connects Different Posts Together
- Pull Latest Forum Posts within WordPress
- How to setup a membership system in WordPress?
- Where’s did this div element come from?
- query_posts meta_key with current date
- How to activate flash cards
- Add array of post id’s to a category?
- Transferring theme and imported post attachments
- Adding pub_Date to an RSS feed hosted on WordPress