Please use below file permissions if you are unable to update plugins or themes. Make sure of the file group and owner for proper protection.
find . -type d -exec chmod 774 {} \;
find . -type f -exec chmod 664 {} \;I had applied these settings, because I had my personal VPS and didn’t worry about other users. If you have other users on same server then file group and file owners make a significant impact.
Linux permission:
7 5 5 user group world r+w+x r+x r+x 4+2+1 4+0+1 4+0+1 = 755