I am using survey123 services and have an express server that saves the response to my machine on submit.
I am using a temporary token generated from the dashboard of ArcGIS (i.e https://developers.arcgis.com/dashboard/) but I am unable to post any request to ArcGIS services using the temporary token, I also tried to generate the token from API but ended with the same error i.e
When you say survey123 services I assume you are talking about the feature services that are created when a Survey123 survey is published.
I would suggest reaching out to Esri Technical Support for assistance formatting your request to the REST endpoint of the service, as well as checking out the documentation for the specific request you are sending.
If you are trying to make a request to the Survey123 REST API (this is different from the REST endpoint of the feature service), please check out our REST API documentation.