Hi friends.
I am trying to develop a SMS solution for our business.
We use Soprano (Telstra) as our telephony carrier to deliver SMSs.
They have supplied a developer guide pdf which doesn't include information regarding PowerAutomate.
Unfortunately, I have been unable to successfully send a SMS as yet.
The below is the sample code from their guide:

Here is my FLOW:

The FLOW does authenticate in step HTTP auth and provide the accessToken in the response.
But FLOW step HTTP sen errors out. eg. {"statusCode":401,"statusText":"Unauthorized","errorCode":401101,"errorType":"CLIENT_ERROR","errorDescription":"User cannot be authenticated"}
Any help would be appreciated.
Thanks, Dan