Hi @Ninja, in the first instance I had problems with the correct display of the MAPS modules within the articles of the 'city-guide' template. I first updated the System -JA GOOGLE MAP plugin, I thought I had successfully created and activated a new GOOGLE MAPS API but inside the modules I kept seeing a gray text overlaying a Javascript ERROR. I went back to the NEW GOOGLE CLOUD PLATFORM, and from there (after logging in with the credentials with which I also pay for Google services such as Gmail) I registered the new domain, and by going to CREATE CREDENTIALS I was able to create the new API, copied to the Plugin System Ja Google Map and everything went well.
Thanks @Ninja.