@leif Hi there, thanks for your question on accessing the Google Maps Tile server in FME. Based on our investigation of this matter, it appears that these various “mts” links are older links to the Google Maps Tile servers, and are no longer authorized access points for general user accounts. In recent years, Google began restricting access to many of its web services, including the Maps Tile servers. Please see Google’s official documentation here for more information:
https://www.google.com/url?q=https://developers.google.com/maps/documentation/tile/overview&sa=D&source=docs&ust=1664460281010053&usg=AOvVaw0ROcJGH79VvV8H-QR1GKTR
Parsing through some of the other documentation that Google provides on the Google Maps Platform (available here), you'll notice that many of the Google Maps API endpoints now require billing information and valid API keys in order to access the various web services therein.
Some of the older endpoints to the Google Maps Tile server can still be readily found online, but may be restricted unless you have appropriate permissions granted to your user account by Google. This issue is a permissions issue with the API provider, rather than an FME translation error, and is something that you would have to contact Google about if you require access to this web service.
I hope this information helps you with this issue! Please don't hesitate to reach out to the FME Community again if you require further assistance with your FME translations and / or automations!