Sorry for incomplete answer,
Use the 301 redirects.
This link give an idea about redirects https://moz.com/learn/seo/redirection
https://wordpress.org/plugins/simple-301-redirects/
For the wordpres there are free good plugins for add html / htm extension to urls.
This for – “.html”
https://wordpress.org/plugins/html-in-url/
I think you can edit it and change it to “.htm“
If you dont want to use plugins,follow this and change it according to your requirement,
Related Posts:
- Running Gutenberg React in Development Mode
- Is there a blank theme framework compatible with WP 3.0? [closed]
- Plugin SVN & update API – how are plugins identified?
- WordPress hook before inserting post into database
- Check for and enforce unique value in user-entered custom meta field in WP Admin
- Custom Search Query
- Enable / Add Custom Keyboard Shortcuts To Work With WordPress’ HTML Editor
- Removing fields from the Media Uploader/Gallery
- Managing Images for a WordPress Blog: Picasa or Flickr?
- How do I add Post Like and Bookmark Functionality to my WordPress Site?
- How to exclude certain widget from showing up on home/front page? [duplicate]
- What is causing this error? “Warning: Invalid argument”
- How wp_ajax_nopriv since WordPress 3.1
- Modifying loop on a custom page, strange behaviour
- WordPress native “playlist” shortcode. Next and Prev there are but with no icons. How to fix?
- Add filename to attachment page url
- Show post page only if the user has bought a specific product
- custom headers for static home page and posts page
- How to redirect WooCommerce shop URL?
- Best way to implement a thumbnail-based gallery in WordPress?
- Why is my mod_rewrite not working?
- Create simple Cookie Box for WordPress
- How to remove buttons from the WP Editor on the edit post page in the admin area
- Does wordpress prevent non wordpress pages from being allowed on the same domain?
- Different development environments (Mac & Windows)
- WordPress Locale Switching on Accept-Language Header
- How to add custom page attributes in WordPress?
- How do I call in a category title on a category page in a child theme?
- Include custom JS without child theme
- WordPress media uploader – upload tabs not hiding
- how to convert Html block to dynamic widget?
- Is there a way to set the value and text for Select/Radio/Checkbox using More Fields?
- Custom Log In Screen – Disable password recovery [duplicate]
- the_post_thumbnail() returns nothing even though has_post_thumbnail() returns true
- orderby in query_posts
- How to get every custom taxonomy names and urls?
- How to customize and keep things up-to-date?
- Problem with custom user meta field
- What are “best practices” for wp-config.php
- Instant install of wordpress
- Problem with theme activatation
- How to customize feed?
- Two description meta tags All in One SEO WordPress [closed]
- Basic Authentication problem with custom API endpoints
- Moving wp-content folder
- How to update theme from localhost to online site
- Don’t change Custom Post Type slug to unique value
- Is it necessary to use Timthumb in WordPress 2.9+?
- How to show wp.me shortlink underneath each post?
- Shop page custom buttons which is visible to only administrator
- Change admin avatar only (without Gravatar or plugin)?
- Insert menu with a custom walker into page / post body using shortcode?
- Is it necessary to prefix theme_mod, section id and panel id in the customizer?
- Query for specific custom field
- Woocommerce custom field calculation
- Dynamic Control in customiser
- How to auto add nofollow to links in custom field?
- How to load a mycred hook from a plugin?
- toggle Multiple Loop with tittle
- problem saving/ retrieving custom meta with wp alchemy metabox
- What are some good resources for teaching end-users how to use WordPress?
- How To make Custom page of every Category
- Is it possible to add custom badges to product attributes conditionally, based on custom field?
- Created Custom Block – When I come back to edit post/page and change my block content – Update button stays disabled
- Global theme customization multisite
- Measure time in ONLY HOUR format
- How to style bootstrap container in WordPress?
- Floating CTA Image Integration
- Contact form 7 ajax response true/false based on some condtion
- How to add custom classes to a WordPress theme HTML tag?
- Altered Media Library URLs
- Displaying Child Page’s Information
- generate a static copy of the website footer html
- Multi-site customization
- Query 1 custom post type, each day, alphabetically
- Admin menu disable new/delete page
- Show different pages on site depending on user choice
- Is there a way to limit multi upload in media upload box?
- SAving PHP in custom wordpress option field
- Does WordPress support template resources/custom fields
- Change default “Apply Changes To” radio option when editing images
- How to loop through 1 CPT with 2 Taxonomies
- Pulling posts into static site (wordpress as subdirectory)
- Call a duplicate registration form with other url
- If I delete my wordpress site then does that delete all my sites?
- How to support extra color options for shortcodes?
- Remove Twenty Twelve themes responsiveness in Internet Explorer
- retrieve theme custom settings
- Looking for a way to take readers to random post when clicking a link
- pull custom fields values from wp-database in a nested foreach loop
- Customise default site setup
- Adding a third custom taxonomies
- Pass query param to custom page
- Custom CSS File wont work on second Page
- How to create a shortcode with HTML code in it and custom parameters/
- responsive screen not working [closed]
- Storing form data into wordpress database [closed]
- User Query Multiple Orderby Clause
- How to display product variations on same row
- Create a page for each database table entries