Assembly.ai + bubble app

Hi
I have been trying to implement the Assembly.ai plugin to my app and I am not sure how to make the transcript from audio file. I just want to see how this plugin works and studied some point by point tutorial in Bubble but still not sure how to do this.
Please help me with this problem.
I can see the two data calls(assembly-transcribe and assembly-transcribe result) provided by plugin but no elements or actions provided.
Please help me with this problem.
PS: this is not the real-time assembly.ai plugin but the free one which says can help you with audio transcribe.