When you open your Greenhouse instance and generate a Harvest API Key for Hatch you will need to following the following steps and provide the following permissions.
Step 1: Log in and click the Configure (Settings) Icon on the upper right-hand corner of any page.
Step 2: Click Dev Center in the left menu.
Step 3: Select API Credential Management.
Step 4: Click the Create New API Key button.
Step 5: Select Harvest for the API Type. Enter a description for the API key and click Manage Permissions.
Step 6: Click the Copy button, and paste the API key below. Next, click I have stored the API key. Please note: you will not be able to copy this API Key again, so please store it somewhere safe!
Step 7: Select your permissions.
Step 8: Enter the API Key in Merge Link