I want to update my iphone just to 16.7

That is not possible. Nor is it advisable.

Update your iPhone as follows:

Update your iPhone or iPad - Apple Support

You will receive the latest security enhancements, defect repairs, feature enhancements, etc.

The current iOS version is 17.1.

If you look in settings for updates it should initially offer the last iOS 16 update if you don’t have it and then further down an option to do iOS 17. If that doesn’t show you won’t have the option via that method. It still shows that way on the lone iPhone 12 in my house that we haven’t updated to avoid any of the issues that iOS 17 was having with the screen time app (a minor uses that phone).