Sigma function call hangs forever from Desk widget — app_install_id/encapiKey are null

Sigma function call hangs forever from Desk widget — app_install_id/encapiKey are null

Calling ZOHODESK.request() from the widget to invoke a Sigma DRE function URL hangs forever (never resolves, never rejects, no error) until client timeout. Tried with merge fields app_install_id={{sigmaInstallId}}/{{installationId}} and encapiKey={{enCapApiKey}} as documented — same hang every time.

Proof the merge fields have nothing to resolve: I had the Sigma function itself return its own execution context via data.get(...). Result:
  1. {"app_install_id": null, "encapiKey": null, "integ_scope_id": "123456789", "sigma_execution_domain": "123456-12358-12565-8641-04b0c2454d1f.sigmaexecution.eu"}
How do we generate/link a valid app_install_id and encapiKey for this installation so the merge fields can resolve? Is there an extra setup step required for "personal" type extensions?

Thanks for insights