Is there a way around this?

I'm wanting to upload an edit I made but tiktok won't let me use the song I used. Thing is, the song is already available as an audio (its Wildflowers by The Wailin' Jennys) and the video is shorter than 60 seconds! What gives? I'd just use the audio but it's not cut to the right portion of the song. Is this a bug? How do I get around this? I've been working on this edit for a week, I want to share it with people