Screen problems
I have a white line from top to bottom on my screen.
iPhone XS Max, iOS 14
Question marked as
Top-ranking reply
First try a Forced restart
https://support.apple.com/guide/iphone/force-restart-iphone-iph8903c3ee6/ios
If no better
You should arrange a service or repair
https://support.apple.com/iphone/repair/service
Anything other than Screen or Battery may be a replacement phone and the price is in the article.
If not covered by warranty and you don't have AppleCare+, you may have to pay full replacement cost for severe damage
You can see additional service information within the following article:
Get your iPhone, iPad, or iPod touch ready for service - Apple Support