Registerant Id from past meetings of participants

I am not getting registerant id of the participants other information I am geeting but not this one I highly rely on this for my backend calculations.

steps to get registerant information
pass accesstoken along with the meeting id with the link‘.$meet_id.’/participants?include_fields=registrant_id

but not geeting registerant id of the participants other than host

Hi @niteshexact !
Thanks for reaching out to us!
Could you please confirm if the meeting that you are querying had registration enabled upon creation?
If not, it is expected that you can not get the registrant id. This field gets generated only when participants register to a meeting or if you add them via API
hope this helps,