As of July 2023, you can connect as many Google Ads accounts as you'd like to a single domain name in your Fraud Blocker account.

Here is an example of how that looks in the "Advertising Setup" area of your account:

Note: we currently do not allow connecting of multiple domain names to the same Google Ads account and we are working on releasing this feature soon.

See this article for steps to connect your Google Ads account.