Simphony STS Gen2 - Post check error

[jonatanhdz]

Hello,
I'm trying to use the Simphony Transaction Services Gen2 (cloud) API to integrate restaurant orders from a mobile application.

I've followed the documentation to configure the following:

• Enabled Simphony Transaction Services Gen2 (option 74) in the Revenue Center where the Checks will be created.
• Created a Workstation of type POSAPI Client, enabling the Simphony Transaction Services (Gen2) Location API and Simphony Transaction Services (Gen2) Cloud API options, and configured the Workstation where I want to create the Checks as the Service Host ID.
• In the Transactions tab, selected Minimum Check Number, Maximum Check Number, and Default Order Type.
• In the Revenue Centers tab, selected the Revenue Center enabled in the first step.
• Created an Employee with Employee Level 0 and permissions for the Revenue Center that will be used.

This has allowed me to successfully use the following STS Gen2 API groups:

• Configuration API (to retrieve the menu from the Revenue Center)
• Employees API (to get the employeeNumber)
• Organization API (to get Locations and Revenue Centers of the organization)

However, when I try to use the Checks API group to create a new Check or retrieve the list of today's Checks, I get the following error:

{"title":"General Service Error","status":503,"detail":"User is not available","instance":"error:userOrproperty-not-available"}

Does anyone know why I'm getting this error?