Fix a WordPress site

PROBLEM
There is a site on react which lies at the address site.ru
And there is a blog on Wordpress that lies on another hosting but opens at site.ru/blog/
For all this to work in this way I had to make a redirect in .htaccess
The blog works, all posts and categories open normally.
But half of the plugins for WordPress do not work and gives a 404 error when trying to save changes.
For example Yoast SEO

TASK
Make the plugins work.

WHO IS NEEDED
A specialist who had experience setting up a WP site on another platform on one domain (not a subdomain). Obviously you need devops knowledge because its not about WP.

FURTHER
Send links to example sites where you have already set up this and your contacts for communication.
If you have not had such an experience - please do not respond to this ad.