After you've chosen the Trigger or Action you'd like for Basecamp Classic, next up is authentication. Here is a quick guide on how to connect your Basecamp Classic Account to Zapier.
First, click to connect a new Basecamp Classic Account.
You'll get a popup asking you for two pieces of information:
Account: The subdomain in the your browser's URL bar, when you are logged in to Basecamp Classic.
API Token: This is a secret token that allows Zapier to access your data. Follow the guided screenshots below or the directions on screen to find your API Token.
First, inside a new window or a new tab, log in to Basecamp Classic. Note the part in front of "basecamphq.com"
Click on "My Info" in the upper-right corner.
Now on the bottom, find the "Authenication tokens" block.
Click "Show your tokens". Copy your "Basecamp API" token to the clipboard.
Finally, come back to Zapier and type/paste in the correct values:
Be careful that you did not include any extra spaces when copying your API Token. When finished, click continue, and if everything goes according to plan, your Basecamp Classic Account is now connected to Zapier!