Great app: i3D Movie Maker for iOS and Macs with Apple Silicon

 https://apps.apple.com/us/app/i3dmoviemaker/id1560663523

i3DMovieMaker

This iOS app will allow alignment and conversions of Side by Side videos into Anaglyph versions

It's worth the money and a lot easier to use.  The best part is if you have a Mac with Apple Silicon the App works also.