Hi Community,
I'm Gidion from Kenya, I am trying to send SMS Messages using AppSheet automation bot, but It is not working. the platform am using is Africa's talking, I have tested the End points using postman (sandbox), and it seems to be working correctly, see the image below.


But after trying to incorporate the same headers and body data in my automation bot, this is the error message I'm receiving under monitor bot dashboard:
Task Properties
{"Exception":"Webhook HTTP request failed with exception The remote server returned an error: (400) Bad Request. ","Task Type":"Webhook","Task Name":"Task for Send SMS Via Africas Talking 2","Url":"https://api.sandbox.africastalking.com/version1/messaging","Verb":"Post","MimeType":"application/x-www-form-urlencoded","Headers":"apiKey:atsk_67691d347182179506e0830d27cb6a84cf8aec482e49013cf2e422ccfe5b6a8a9b9ccaa9, Content-Type:application/x-www-form-urlencoded","Payload":"username=sandbox&to=%2B254797715518&message=Appsheet\n"}
The following are my screenshots of how I have set up the call webhook automation.



I would really appreciate any suggestions of how to get through this blocker, thank you so much.
Warm Regards,