forget passcode of iphone 7

See instructions in: How to remove your iPhone, iPad, or iPod touch passcode without a computer - Apple Support

If that option is not available, you will need to use a computer. See: If you forgot your iPhone passcode - Apple Support

If you don't have a computer, see the following from If you forgot your iPhone passcode - Apple Support

If you don't have a computer and you can't borrow one, you need to go to an Apple Retail Store or Apple Authorized Service Provider for help.

See the article If you forgot your iPhone passcode - Apple Support

If you don't have a computer and you can't borrow one, you need to go to an Apple Retail Store or Apple Authorized Service Provider for help.

You can ask them , I don't think they will charge for it .