I’m still in the process of learning using Sandbox. I did learn and follow the instructions (documentation) and found out the following error/problem:
Send Message Node → Question: where to find Target Device ID?
Retrieve Message Container → “Error returned from Catenis API endpoint:  No permission to retrieve message container” → Question: how to get the Permission to Retrieve Message Container?
Retrieve Message Progress → “Error returned from Catenis API endpoint:  Invalid or expired ephemeral message” → Question: is this referring to the Message ID I’ve obtained from Log Message?
- Issue Asset Node → “Error returned from Catenis API endpoint:  Invalid holding device”
Note: I’ve inserted “null” in the Holding device ID as per the documentation in this link https://blockchainofthings.com/issue-asset-node/ but the error still occurs.
Appreciate your technical advice, thank you.