MAP View google map issue "For Development Purpose Only"

I am using MAP view in scheduler, right now I am getting error message “For Development Purpose Only”.
Example:
https://docs.dhtmlx.com/scheduler/samples/03_extensions/19_map_view.html

Anybody help me to resolve it…

Thanks in advance

Unfortunately google Maps is no longer free. You have to associate a credit card so that you can get billed if your site has requests that exceed the $200 credit they give you monthly for free. That is why you get the watermarked maps.

For more information, see: https://cloud.google.com/maps-platform/pricing/

Update:
We’ve updated the sample, so now it should display correctly.
You need to register and add your own google API key on your page, so the maps will display correctly.
Here you can find an info:
https://developers.google.com/maps/documentation/javascript/get-api-key