I am using WordPress on my live server which only uses SFTP using an SSH key.
I want to install and upgrade plugins, but it appears that you are required to enter your FTP login to install the plugins. Is there a way to install and upgrade plugins by manually uploading the files instead of having WordPress handle the entire process?
Just a quick change to wp-config.php
That’s it, enjoy your wordpress updates without ftp!
Alternate Method:
If you're on Ubuntu, a quick solution that worked for me is giving ownership to the Apache user (www-data by default) like so: