Bearer authorization method is a much simpler way of sending API requests.
It makes the hash parameter completely obsolete.
You can find your bearer token under Account Owner Details.
Please make sure you are using https:// protocol, which provides encryption for your requests.
Example curl request:
curl \
-H "Authorization: Bearer BEARER_TOKEN" \
-H "Content-Type: application/json" \
-X POST \
-d '{"clientId": "CLIENT_ID"}' \
"https://app.gatherup.com/api/test"
Please replace BEARER_TOKEN and CLIENT_ID with your own parameters.