Google now want payment

Today I received an email from Google saying that my sites using the Maps API must have a payment linked to the API after June 11 2018. The email does not say my site will stop working but I am assuming it will. The documentation and setup screens look complex, lots of options that I do not really understand. I put together a simple Joomla website and used Google Maps (ZHGoogleMap) to show the location of places that I wrote about.
Google say they give $200 credit per month so it is unlikely that I will have to pay but it seems that I have to put my credit card against the API that Google gave me to insert into the ZHGooleMaps Joomla addon. There are listed 6 different API for this one site that I can restrict (distance, directions, elevation......) and security like limiting to HTTP domain or IP addresses or mobile app. I do not know which ones I am using.
Any clarifications would be appreciated. Document showing how to setup the API on the Google site would be good.

I got this message too. Today I can't understand it clear.
As for features:
- places - if you enable places in map details to see nearest POI or use autocomplete feature in find by geocoding Control
- directions - if you use find by geocoding and enable build directions, or you enable feature to set placemark as start/end point of route
- elevation - if you enable feature to show elevation for KML file