well the issues were actually 2 types:
1) write your “original website” url exactly as it is published, including https or http one.
2) we had to make some changes to .htaccess, based on our server configuration: we did add at begin of file the following lines:
SetEnv PHPRC YOUR DOMAIN BASE URL/php.ini
LimitRequestBody 999999999999
SubstituteMaxLineLength 20M
You can try this way, but each hosting provider could need a different conf.
TBH this plugin is good with small databases, but with big ones, is not that easy to use.