To use Mapsly inside your Zoho CRM, you need the Single Sign-On activated for your Mapsly extension, as described in the installation guide. If you didn't do it right after installing the extension, here's how to do it later:
Scroll down if needed and find Mapsly extension, and click Configure:
Check the SAML Single Sign-On checkbox:
Now you can open the Mapsly tab and you'll be automatically logged into Mapsly.