Adding / edit files to webroot via Filezilla

Hi i am new with 4 version, can someone please help to give step by step info how to get into webroot since i had tried to change permission /opt/easyengine/sites/ but still failed

thanks to the developer for the hard and great work

I also cannot open the app directory in /opt/easyengine/sites/ “permission denied”

I have updated to the latest easyengine but still I cannot access my wordpress files on ftp.