How i can disable the avatar img compressor?

for now not, sorry, in future we will improve image/avatar field type to choose extension of avatars, now convert all images into JPG

and how i can then the avatar implement it on in a costum login modul?

you can use our content plugin on article or modules (in all content that supports Joomla content plugins).

For example to see avatar:
- create a module of type Custom HTML
- set access to "Registered" - with this only registered users can see this module with own avatar
- set parameter "Prepare Content" to "Yes" - with this the module load Joomla Content Plugins
- In text put this:

{user avatar}

More info about our content plugin here: https://www.easy-profile.com/docs/26-plugin-content.html