Permission issue when adding datssource to Organization through HTTP API

I am trying to add datasource to Organization through HTTP API but receiving failure response as “Permission Denied”.
Here are the steps that were followed:

  1. Create Organization
  2. Create User
  3. Add User to Organization as Admin
  4. Add datasource to Organization with Org Admin user credentials that were created in second step

All the above steps are done through HTTP API. Fourth step is throwing error response as “Permission Denied” while adding datasource.

Please help me on this issue.

Suggestion in issue resolves the problem.