Can’t Export Edited Videos From App to Phone

I’m using Vlog Star to edit a new video for YouTube, trying to revive my channel, and grow it, and I’ve attempted all troubleshooting tips for exporting the edited video, clean up storage, buy more storage, clean up storage again, reduce quality, add watermark back, and it’s still failing to export. The app requires to export the video back to photos before it can be uploaded to YouTube. I really wanted to get it out tonight. Is it a compatibility issue?