Setup multiple contact person for a subscription to get billing / payment notifications for that subscription

Setup multiple contact person for a subscription to get billing / payment notifications for that subscription

Hello Team,

I see the steps to do the same from portal but i tried similar from API with no success.

Post: https://help.zoho.com/portal/en/community/topic/multiple-recipients-to-receive-payment-notification

I used API - Subscription > Add Contact Person and passed a newly created contact person id in the POST call.
That added the contact person to the list of contact person in the subscription, BUT when i go to portal and open up that subscription - "Manage contacts" - i see that the new contact person "Emailed To" is not checked as on.

How to i get that done from API - add contact person and check them On for "Emailed To" feature in Managed contact??

Thanks in advance.