Android Question problem installing ExoPlayer (add library)

[Randomishere]

sorry, I try to put a video in b4a and I saw what they recommend, the problem is that I don't know how to add additional libraries and I get this error

B4A Version: 11.20
Parsing code. (0.01s)
Java Version: 11
Building folder structure. (0.01s)
Running custom action. (0.03s)
Compiling code. (0.03s)
Compiled design codes. (0.00s)
Organizing bookstores. Error
Maven artifact not found: androidx.annotation/annotation-experimental
Source: ExoPlayer

If someone could give me a method please, I'm new to programming and I've never added a library, thanks for your attention

 

[Erel]

1. Use latest version of B4A.
2. Use latest SDK: https://www.b4x.com/b4a.html