how to remove a incompatible app

One option is to just drag the app to the Trash and empty it. However, as noted, some apps do have other parts which are scattered throughout the HD. These can be removed by checking to see if the app vendor has an uninstaller on their web site. Using the uninstaller will normally remove everything.

Which one is it, it may have hidden parts?

We need to see what all is running, a report from this will not display any personal info...

EtreCheck is a FREE simple little diagnostic tool to display the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to help people help you with your Mac. It will not display any personal info.

https://www.etrecheck.com/

Pastebin is a good place to paste the whole report if you capture the URL while there…

Workable but harder for me to work with...the Note tool on the bottom of this editor's toolbar, as shown in the image, to copy and paste the output from EtreCheck. In a Reply before you click post, look for this to add longer texts...