How to Fix "You don't have the permission" on SendMessage (PON-2085785)

Hi everyone,

I'm trying to send a message reply to a negotiation using the following REST API endpoint in Oracle Fusion Cloud:

Endpoint:
https://xxxxx.oraclecloud.com:443/fscmRestApi/resources/11.13.18.05/supplierNegotiations/action/SendMessage

Method: POST
Content-Type: application/vnd.oracle.adf.action+json

Request body:

{
"parameters": {
"ThreadId": 300000006208003,
"AuctionHeaderId": 300000005958444,
"BroadcastType": "ALL_INTERNAL_MEMBERS",
"MessageType": "INTERNAL",
"ParentMessageId": null,
"MessageSubject": "RE: asunto test",
"MessageText": "Mensaje de respuesta TEST"
}
}

However, I'm getting the following error response:

Error:
You don't have the permission to perform custom action SendMessage. (PON-2085785)

Has anyone faced this issue before?
Do you know what role(s) or privileges are required to successfully call this action?