If you opted out during the 30 day period before any money moved, you will receive a confirmation of your opt out. You can enroll again at any time through your employer or directly in the app.
If you opted out while contributions are in progress of moving to your Xiggit account, you must wait until any money in the process of transferring is done. All future deductions are immediately stopped. Once all contributions are in your Xiggit account, you will then have to determine what you wish to do with your retirement money.