1. The first step is to log into your Merchant Center.
2. Click the three vertical dots in the top right-hand corner, choose “Account linking” and click "Link account"
3. Find your AdWords account number by logging into AdWords with your credentials, insert it into the box in the format xxx-xxx-xxxx and click “Send Link Request”
4. Go to AdWords, click the settings symbol in the top-right corner and choose “Linked accounts”.
5. Select “Merchant Center” from the menu on the left side. Click “Show Request” and then “Approve”.