When you set up a Performance Max campaign without using a Hotel Center account, the hotel rates that are used for your ads are Google sourced third-party rates. Your hotel ads will display third-party rates that are sourced by Google.
You can’t change the hotel rates shown with your ad. Google maintains a high price accuracy standard on the hotel booking module and automatically filters out any feeds with a low price accuracy score from being used.
You can’t modify the booking link URL. This is configured to the booking website of the hotel that you’ve selected for your Performance Max for Travel Goals campaign. However, you can modify tracking URL parameters on the account level by navigating to “Campaign URL options” under “Settings”.
Note: The advertiser remains solely responsible for their ads.