Click Add integration in Settings | Integrations and Keys, and search for Monday. Click Continue, specify a key name, and click Save.
In the Integrations list, where your key is now included, click Authenticate..
Follow the instructions and get your key and paste it into the dialog.
Useful links:
To verify that the connector is set up correctly, do the following.
Add a new action in a script.
Search for the actions related to Monday, select the one you need, and click Add.
Fill out the inputs.
Assign the key you created earlier.
Run the script and take note of the output in Transposit.