Go to Coinbase
Log in or create a new account on https://pro.coinbase.com/
Open account dashboard
Click the menu button in the top right corner.
Follow to API
Click "API" on the left side menu.
Click "New API Key"
Name your key
When you have multiple APIs, a proper name helps to manage it.
Select permissions and passphrase
For trading on 3Commas "View" and "Trade" permissions are required.
Enter 2FA code
Click "Add an API Key"
Copy Secret API Key
You will see confirmation Coinbase API created.
Go to My Exchanges page in 3Commas
Find Coinbase in the list
Connect Coinbase to 3Commas
Enter Coinbase API key name (4)
API Secret Key (3)
Click on Connect an exchange