Restrict Users access to login into CRM?

Restrict Users access to login into CRM?

I’m wanting my employees to be able to utilize the Zoho CRM Lookup field within Zoho Forms. For them to use lookup field in Zoho Forms it is my understanding that they need to be licensed for Forms and the CRM. However, I don’t want them to be able to login into the CRM. Is there a way to have them licensed for the CRM so they can utilize the lookup field in Zoho Forms but not login able to directly login to the CRM?