Restore without updating

I’m trying to run an app(that doesn’t work anymore on 26.3) on my iPhone 11 that still has ios 14.6 on it but I forgot my password, is there anyway to restore my iPhone without updating it? I tried using Apple devices but I would have to update and restore. I’m fine with updating up until ios 26 since the app I’m trying to use doesn’t work. Is there any work around or anything I can do?