How to add SSL certificate manually via terminal

[Grkmyldz148]

/etc/letsencrypt/live/${subdomain}/fullchain.pem

And

/etc/letsencrypt/live/${subdomain}/privkey.pem

Even though I give the correct SSL certificates to the paths, my site does not detect the SSL certificate, but when I give it through the interface, it works. Is there a way to do this manually?

actually https://serverURL/websites/saveSSL
I have to manually do what the endpoint does.