Zoho CRM for iOS app: Where did my message button go?

Zoho CRM for iOS app: Where did my message button go?

I have recently begun using this app on my iPad Pro more and one day it had a message button along the bottom where I could see emails, and the next day it's gone.  Have I done something wrong and can I get it back?  I no longer have access to emails within the app.  Thank you for your help.