Thanks for your answer, Eason. I checked SSA(Secure Service Account API) and followed all the steps. I am getting the 3 legged token without user input, but I am getting an error on the response when trying to get the status of the model (commands:autodesk.bim360:C4RModelGetPublishJob):

"status": "403", "code": "C4R", "detail": "Failed to get publish model job"

I am accessing the Hub, the folder, the file and project Id. I provided to the Service user with "manage" permissions settings. Scopes are data:create data:read and data:write, as mentioned here: https://aps.autodesk.com/en/docs/data/v2/tutorials/publish-model/ I made it working before with 3 legged token with user authenticate.

I found a link about Secure Service Account which mentions this: "Revit Cloud Worksharing (RCW): Full compatibility with Revit Cloud Worksharing" https://aps.autodesk.com/blog/update-secure-service-accounts-ssa-goes-ga So, I was expecting it will allow me to publish, since it mentions "Full compatibility".

Can you confirm SSA should allow me to publish (commands:autodesk.bim360:C4RModelGetPublishJob and commands:autodesk.bim360:C4RModelPublish)?