How to allow access to only 1 page?

Question

htaccess

There is a site in the local network, a smart home and all that. He has an API for VK and other nonsense :) The site was transferred from hosting to my machine and now I'm sitting thinking :)
I need to allow access to the API directory to everyone, and close access to the rest of the site to everyone except for local network devices ...
I understand that I need to write a rule in htaccess, but I don't know how :(

Answer 1

In the root directory create a .htaccess file and write:

Order Deny,Allow
Deny from all
Allow from 10.0.0.0/8
Allow from 100.64.0.0/10
Allow from 172.16.0.0/12
Allow from 192.168.0.0/16

in api folder create .htaccess file

Order Allow, Deny
Allow from all