To use the Google Search Console for your website, you need to confirm that you are the owner of the corresponding domain. This is also a prerequisite for using your domain with other Google services like Google Sites.
Log in to Google Search Console.
The Select Property Type window opens.
In the Domain (not "URL Prefix") section, enter your domain.
The Verify Domain Ownership via DNS record window opens.
Click on START VERIFICATION.
The IONOS login page opens in a new tab.
Log in to your IONOS account and click Connect.
In order for Google to verify you as the domain owner, you must allow Google to access your domain's DNS settings. To give your permission, click Allow.
The IONOS tab closes automatically.
Switch back to the Google Search Console.
The Ownership auto verified window is displayed.
Click GO TO PROPERTY to open your domain in Google Search Console.