Visit the DonorDrive instance you wish to integrate with. Make note of the domain.
For example: if you visited https://testdrive.donordrive.com you would access the API by appending one of the resource endpoints cataloged below: https://testdrive.donordrive.com/api/events.
If there's a particular how-to you don't see listed below or in the Demos section, don't hesitate to put in an issue.
https://testdrive.donordrive.com/api/events
https://testdrive.donordrive.com/api/events/508/teams
https://testdrive.donordrive.com/api/teams/8580/participants
https://testdrive.donordrive.com/api/participants/15882
https://testdrive.donordrive.com/api/participants/15882/donations
https://testdrive.donordrive.com/api/participants/15882/donors?limit=1&orderBy=sumDonations%20DESC
https://testdrive.donordrive.com/api/events/508/participants?where=displayName%20LIKE%20%27%25bob%25%27