While login in Ring Central with Zoho CRM, it is saying that You need to have Office plan ???

I have integrated Ring Central with Zoho CRM. I have taken the professional plan for Zoho CRM. Also i have taken Pro Plus plan for Ring Central. So whenever i am trying to login in https://crm.zoho.com/crm then it is saying that unable to login / You have to take office plan for ring Central. So now i am confusing what is the process for Ring central plans for integrating with Zoho CRM ???