Zapier thinks about software integrations in terms of Triggers and Actions. Activity in one app triggers a resulting action in another app without requiring you to do any work.

You will need to create an account on Zapier. Once you have created an account and logged in, click the Make a Zap button.

Look up Donorbox as your trigger app. 

 You will then need to connect with Zapier. Your username will be your login email. Your API key can be found here.

If your connection is successful, your trigger will be ready.

Once you have connected to Donorbox successfully, you will be able to choose any other platform to select your action.