A client is using manual bidding for its Shopping campaign and you decide to use target return on ad spend (ROAS) to take advantage of Google Ads’ automated bidding features. Before you begin using target ROAS, you need to make sure that:

each product group in the campaign is restructured so that it has fewer than 200 clicks per week
conversion tracking is set up for the campaign and each product group has more than 200 clicks per week a
remarketing list for search ads is set up for the campaign
the client is using a third-party bidding platform that is compatible with target ROAS