If you see the above warning at your merchant centre account. Then follow the following steps to set up Product listing ads.
- Go to Settings -> Adwords. Then click on "set up product listing ads campaign"
- Enter the name of your campaign and click on "Create AdWords Campaign and Continue"
- Set your budget and click on "Save Campaign Settings and Continue
If you already have AdWords account associated with your gmail, then you are done. Else create AdWords account or Add and existing AdWords account to your products listing ads account on the next page.
- You can link existing AdWords account to your product listing account by entering AdWords Customer Id in the box provided