You can use the Underdog API Postman to test your Devnet and Mainnet implementations
Overview page for the Underdog API Postman
On the left hand side, click the desired API endpoint: Mainnet API or Devnet API. Within the collection page, hit the Variables tab to set the
apiKeyvariable in your workspace.
Your API Key can be generated from the Underdog Protocol dashboard when you sign in.
Where you can set the apiKey variable in Postman
The Devnet API is free to use and the same API Key you generate can be used for both endpoints. You will need a subscription to use the Mainnet API.