I heard back from Google support on this and here's what they told me:
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If you open the dev tool and check the Console tab you will see the error is due to a missing API key in your script.
Keyless usage of Maps API has been deprecated since the 16th of September.
This is the script that fetches the API in that web page:
<script src="/http://maps.googleapis.com/maps/api/js?sensor=true&libraries=places" type="text/javascript"></script>
You need to include the API key there and remove the sensor parameter that is no longer required.
Here is an example:
https://developers.google.com/maps/documentation/javascript/examples/map-simple
<script src="/https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap"
async defer></script>
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I did see the error message they mentioned in the Console and when I looked at the page source sure enough I found this:
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.SpGeoMapMod img { max-width: none; }
</style>
<script src="/http://maps.googleapis.com/maps/api/js?sensor=true&libraries=places" type="text/javascript"></script>
<script type="text/javascript" src="/http://tournamart.com/components/com_sobipro/var/js/xxx.js"></script>
<script type="text/javascript">
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and the URL I had specified in the SobiPro GeoMap Module's Google API URL field is missing. Just to see if it EVER showed up I changed that field to
https://maps.google.com/fluffy and then looked at my page source and found that that DID show up but AFTER the above googleapis url rather than replacing it:
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.SpGeoMapMod img { max-width: none; }
</style>
<script src="/http://maps.googleapis.com/maps/api/js?sensor=true&libraries=places" type="text/javascript"></script>
<script type="text/javascript" src="/https://maps.google.com/fluffy"></script>
<script type="text/javascript" src="/http://tournamart.com/components/com_sobipro/var/js/xxx.js"></script>
<script type="text/javascript">
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So then I changed it to what the Google folks told me to use,
https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap, and looked at the source again and we were back to the original situation where that URL did not show up.
That told me that SobiPro was filtering out URLS that contain the googleapi text so I installed URL redirecting software (ReDJ Community from
http://www.selfget.com/downloads/category/3-redj.html) on my site and created a dummy URL (
http://tournamart.com/sobimapapi) that forwards to the real URL with my API key (
https://maps.googleapis.com/maps/api/js?key=YOU_API_KEY&callback=initMap) and put that dummy URL in the SobiPro GeoMap Module's Google API URL field and now my map displays. I had to set Decode URL to yes and every other option to no in the ReDJ list of options for this redirect.
If you don't have redirection software on your site you can do the same using
http://tinyurl.com or similar but then you'd have to update your Google Cloud Platform permissions to allow tinyurl.com to use your API key (assuming your currently have it restricted to just your sites IP address).
So, if you get a "Something went wrong" displayed on your map and a "Referer Not Allowed" error in the Console:
Google Maps JavaScript API error: RefererNotAllowedMapError
https://developers.google.com/maps/documentation/javascript/error-messages#referer-not-allowed-map-error
Your site URL to be authorized: http://tournamart.com/
when trying to display your map then click on the URL in the error or go to
https://console.cloud.google.com/, log in, select your project and Enable APIs -> Maps JavaScript API -> Credentials -> Click on your key name -> change Application restrictions to None (or do whatever else you feel is appropriate to allow those requests).
Hopefully SobiPro will have a real fix soon.
PS the "=initMap" at the end doesn't seem to be necessary and causes an error message in the Console window.