Campaigns does not allow me to choose my secondary address for sender address

Campaigns does not allow me to choose my secondary address for sender address

Hi, I have added and verified a secondary email address for my zoho account. I want the secondary to remain the secondary address, but I would like to use it as the sender address for my campaigns. I get a notification, "you have already reached the maximum limit to add the sender address. What are my options to indeed use my secondary address as the sender address?