What
@Nick says, if you are on a iPhone it is likely much easier for you to upload directly to YouTube.
So, you have a iPhone it seems, yes? What is your computer, laptop or desktop? What is your exact OS? WinXP, Win7, Win10 or Win11? If you like we could do something like TeamViewer and I could help remotely. I come from many years of support (decades actually), though its more of enterprise broadcast clients but PC/Software support is support ;-)