in Mattermost this works:
/tool fetch mode=https url="https://test.test.com/hooks/suchhookmuchwow" http-method=post http-data="payload={\"text\": \"[Device.FirstAddress] - [Device.Status]\"}"
in Mattermost this works:
/tool fetch mode=https url="https://test.test.com/hooks/suchhookmuchwow" http-method=post http-data="payload={\"text\": \"[Device.FirstAddress] - [Device.Status]\"}"