You should enter your W-2 exactly as it is. Your employer may have added your tips to your W-2, but if they didn't that is okay, but you don't add them yourself. There will be a screen that asks if you had tip income after you enter your W-2 - that's where you'll enter them. Please follow the directions below to enter the tips in the right area.
https://ttlc.intuit.com/replies/3300508