My Iphone 7 says iphone is disabled connect to itunes. what do I do?

if you don’t have a backup, back up your device by selecting ‘back up now’ in the menu

your post implies that if the OP does not have a backup, that they can back up their phone during this process..

if the iPhone is disabled, it is too late to make a backup.. all that can be done is restoring from a backup that was made prior to the iPhone becoming disabled

If you forgot the passcode on your iPhone, or your iPhone is disabled - Apple Support

Your iPhone needs to be restored. Connect you iPhone to a computer via a USB cable (if you have a Mac running macOS Catalina or later, open finder and your device will be in the menu, if you have a Mac running earlier versions or a PC, open iTunes and click on your device). Then in the iTunes menu under ‘summary’ on your device, click restore iPhone (WARNING-this erases everything, if you have a backup to iCloud or to a computer, you can restore from a backup after the restore, if you don’t have a backup, your data is lost). The iPhone will take 5-10 minutes to restore, after, follow the setup instructions and restore from backup to retrieve your data.