Short version: You can’t. Long version: Technically there are ways this can be achieved but they are ① likely not available to you as a user on a shared server where you do not have root permissions and ② even if they were, they come with ‘gotchas’ that you really don’t want to deal with. … Read more
Dissolve Multisite while making site #5 the main site?
A URL like /blog/abcd…/ will redirect to the 404 page, you can redirect the 404 page to the blog page, This plugin will do what you want.
WordPress blocking/preventing viewing of .cgi file in subdirectory [closed]
From 403 error to 500 internal server error
Remove Parent Category from Child Category URL
You can use question mark: RewriteRule ./?$ /index.php [L]
Per the OP’s comment: I found trailing slash is missing is wp_options table in SQL, which is showing two blog sites running as multisite. Fixed the trailing slash site pointing correctly.
Map alt domain to specific section of website w/o MU
Rewrite my default post URL