You can either go to the Zoho Marketplace and install the extension or log in to your Zoho CRM account to install.
To install the extension
Click Setup > Marketplace > Extensions > All.
All the installed extensions are listed. Under All Marketplace you can view all the extensions supported in CRM.
Click All Extensions, browse and click Address checker for Zoho CRM using Google Maps.
The details about the extension will be available.
In the following screen, check the Allow Marketplace vendors to contact me regarding product offers and promotions and click Install.
Check to agree on the Terms of Service and click Continue to Install.
Choose Users/Profiles and click Confirm
Then take a 10-day free trial or take a $7 monthly payment.
Put Google API key in below