Generally speaking, we highly discourage you from leaving a shift incomplete. You've signed up for and committed to a shift start and shift end time and we request you to abide by those.
That being said, we understand unexpected emergencies come up. In such cases, it is important to speak with the shift supervisor and make them aware that you have to leave, and share details around why. Then, they will give you the clock-out code so you can 'finish' your shift on the app at the time you leave the shift.
If you leave the shift location without informing a supervisor, you will be considered as having "abandoned" the shift and you may not be able to return to that business to work again, in addition to having your worker metrics negatively impacted and have the risk of account suspension.