We are trying to post the public note using the product API (/api/v2/tickets/:id/notes). In the body, we are sending the user_id which is the id of the another admin or account admin in that helpdesk. We are getting the error response as “You are not authorized to perform this action on behalf of this user. id:agent-id, name:agent_name” . Is it possible to post the note on behalf of another admin or account admin ?
With Assume identity feature, public notes can be posted on behalf of the agents in the account with an admin’s API key.
But, it is not possible to post public notes on behalf of another admin/account admin with one admin’s API key. The original admin’s API key has to be used to post replied on behalf of them through the app.
Note: Assume identity feature is available from the Garden plan of Freshdesk only. Refer here  for all the available features based on the pricing plans.