How to serve index.php from different directory through .htaccess?

Question

I am working on a project which is in Yii2. I have to integrate swagger UI for API documentation. My current directory structure:

current directory structure

This is what the .htaccess looks like:

RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . index.php
<IfModule mod_headers.c>
   Header set Access-Control-Allow-Origin "*"
</IfModule>

When I hit http://xxxx-api.local/swagger/index.php it treats it as a legit API and because there is no such controller and action it returns 404.

My question is do we have a way to render index.php from another swagger directory if the user hits this http://xxxx-api.local/swagger/index.php URL in the browser?

I tried to twik the .htaccess but it is not working.