Android Question How do you download and install the maven repo link TapLinx in B4A?

Only the ones that were previously in the GoogleMavenRepository are supported. No 3rd party Maven.
So, speaking about your request, You need to write a wrapper library for it to use it in b4a. You need java knowledge to do so.

Speaking about the new Mavendownloadpossibilities in B4A 7.8:

You can see all downloaded maven files in you SDKfolder\extras\b4a_remote folder.
Check the file installed-components.txt for a complete list of all installed maven repos.
You´ll find here the newest files for all the GoogleServices. Maps, Location, Auth, all Firebase Components.
But only the official ones.

Thank you I will check this out.