The Bitly API can be used to shorten, customize or extract data from links
Sign up or Log into a free Bitly account here. It will take you to app.bitly.com.
A generic access token can be used in most cases (if activity needs to be tracked by end user, follow the link listed below under the OAuth Authentication section). Click on the four line menu icon on the top right of the screen, then click on your name or the large arrow next to it at the top of the dropdown that shows up. Click on "Generic Access Token".
You will need a password in order to generate the token. If you signed up with any other method besides directly entering an email and password:
Enter an email address for your account by clicking the top right menu, your name, and "Email" (if it is not already present)
Sign out and go here to reset your password
The Authentication section of this page has more information about OAuth authentication, which is needed when the history of shortened links by end user needs to be managed and tracked.
Information about the API endpoints can be found here. Within the Bubble editor, each call can be specified as being used as an "Action" or "Data". Choose "Action" to be able to use the call on the workflow tab, and choose "Data" to be able to use the call within the design tab of the bubble editor. The "Shorten Link" API call in the sample app is used within a workflow to shorten links that are inputed by users.