Why cant i download wells fargo app on itunes

Well, your question leaves many holes …

• ”download” … “on i[T]unes - apps have not been downloaded using iTunes for many years. They are now downloaded directly to your iPhone from the App Store.
• The Wells Fargo app requires iOS 12 or later. We have no idea if you meet this requirement.
• We don’t know if you’re in a region that Wells Fargo serves.
• We don’t know if you can download other apps but not this one.
• etc. …