You can delete data for a data type directly from the Data Designer or by uploading a .csv file:
For example, your .csv file contains a Staff ID field that is mapped to the Employee ID field in your Employee data type, which is a unique identifier for the data type. The Staff ID field has values 123 and 789 in the .csv file. The system will delete the data records in the Employee data type with values 123 and 789 in the Employee ID field.
At this point, you can close the dialog box for the data import process. The process runs asynchronously and is visible on your worklist.