To allow users to delete records using the form:
Go to the Share section of your form's settings
Ensure that Allow users to view existing records is turned on
Go to the Security section
Allow users to delete records must be enabled.
Once enabled, the delete button will appear at the bottom of the form.
This setting can be enabled for both standalone and child forms. For child forms that open in a popup/modal, the delete button is hidden in the three dot menu in the top right corner.
Optional: Making the delete button show only when certain conditions are met
In addition the steps above:
Create a formula in Airtable with your condition. The formula needs to return 1 when the delete button should be hidden.
Select the newly created field under Hide delete button
Troubleshooting
Cannot delete record with create access token
This error is shown when creating a new record and displaying a read-only version of said record after submission. Deletion is not currently supported in this scenario. Records can only be deleted when viewing existing records.