We have a blog setup on WordPress and our server is a linode instance which we connect through ssh.
Now when I am trying to add yoast plugin it is asking me for FTP credentials and when I am entering them still it is not connecting.
Please advise on this as we are not able to add plugins to our site.
This is a permissions issue with your server, run the following command in your SSH terminal:
sudo chown -R www-data:www-data /var/www
This will grant your WordPress sites the permanent ability to add/update plugins and themes.