How to create an .sng?

I believe it’s the Beatbuddy manual pdf that says that GUITAR PRO software will do this for us, I have files I created and some are downloaded from the Internet. I’m customizing these because they’re already written so I don’t have to create the drum lines from birth… here’s a new problem, I created a new project. I inserted a midi file in the main loop tab BBM… it plays once no problem when it’s over it stops. Then I cannot get it to play again, unless I delete it and re-insert it then it will play only one time, I can’t get it to highlight the rectangular PLAY Button itself it only plays once from the tiny diamond circled play button on the main loop tab