Do I need a Google API key to use Maps?
As of June 11, 2018 you will need an API key to use Google's Map services. This is generally a good thing and you can read more about it in the docs for the latest version of ProMaps here.
No, but you can add one if you want.
You probably don't need one need as Google allows up to 25,000 map loads a day. The geo coding of addresses is limited to 2,500/day but that is only a problem generally when first integrating after the initial geocode most of our users don't add that many records a day.
Here are instructions for adding and API key to this older version of ProMaps; newer versions have a setting where you can simply paste in your API key.
The Maps url requests can easily be modified to accept your own API key though. The geoCode lookups as part of the script "GeoCodeAddress" for example has a set variable script step that sets the google api URL to the $sc_baseURL var. That would need to be updated to have the api key appended to the url string.
Then the contents of "MapSettings::MapDataTemplate" would need to be updated to reflect the key also. That is just a url for the google maps api script included in the head of the document. So that url would need to be modified in the same way as in the geo code script.
So just make sure those two places include the api key in the url and that's it.