Google Cloud Charges for using Google Maps – Is there an alternative

Hi

I have a number of websites that use Google Maps. One in particular (a travel guide) has dozens. Google has always asked for a credit card to be added to the Google account in order to show the maps correctly – this wasn’t a problem as they had a system of credits which was hard to understand but resulted in me getting a bill of $0 each month over all the sites in my Google Cloud account. Their system has changed and I was billed almost €100 for March! The season is only getting underway so this charge is likely to increase substantially. I am looking for an alternative if possible.
Does anyone know of a map plugin that I can use with a postcode perhaps?
Grateful for any suggestions.

Regards
Tia