Im so confused

This is app looks really cool and all but like it wont let me do anything? It keeps saying my device isnt able to record which is weird because my device is an iPhone and its iOS is completely updated. Please please fix this or at least tell me what to do because this app looks really cool and I wanna try it out!

Razzyyyy about Sing Karaoke and Record Songs with StarMaker, v6.0.6