Map from Google Maps how to set up?

Question

Google Maps

A map from Google Maps (an old version of the API) was installed on the site, where there is no key, respectively, binding to a specific URL. The site works on the HTTP protocol.
Now it's time for the site to work on the new HTTPS protocol. And then the map doesn't show up.
This documentation is clearly not suitable for our case https://developers.google.com/maps/documentation/j...
Can we leave the old version of Google Maps without a key, but apparently in this case improvement is required at the API level?
What tell me? Thanks everyone!