Our expert review service isn't something you add to your return this year, it's a feature built into the version of TurboTax (i.e. TurboTax Assist & Review).
If you'd prefer not to use the expert review service, you can start a new return in another (less expensive) edition of TurboTax that doesn't include this feature. Here's how to start a new return: https://turbotax.community.intuit.ca/replies/3288128