Note: This site explains how to integrate the Google AdWords API, which is no longer being actively developed, with v2 of the Content API for Shopping, which has been deprecated. We recommend migrating to the Google Ads API and v2.1 of the Content API for Shopping.
Once you've requested the link from the Merchant Center, you must accept the link from AdWords to complete the handshake and gain access to Merchant Center product feeds from AdWords. You can do this either through the AdWords UI or by using the AdWords API.
Manual steps
In the AdWords UI, click on the Gear icon, and then select Linked accounts and open the Google Merchant Center Section.
By clicking the View Request button, you can see the details of any requested links and approve or reject them.