You have a MacBook Pro 2018+ with a T2 security chip, which implies you require a functional Logic Board to access and decrypt the hardware-encrypted SSD. If Apple or the AASP can put the laptop into DFU Mode, they can try to recover the data; but, if this is not possible, you may be out of luck if you don't have a backup.
You can call a professional data recovery service like Drive Savers or Ontrack to see if they can recover the data, but they will need to repair the Logic Board before they can even try to access the hardware encrypted data, providing the T2 security chip is not damaged or corrupted. Both suppliers offer free estimates and are highly recommended by Apple. If you want the laptop fixed, Apple or the AASP should be able to help you with professional data recovery. If you want Apple to repair the laptop after attempting data recovery, Apple maintains a list of approved professional data recovery services in your area.
You should always have regular and frequent backups of your computer as well as other external hard drives to avoid data loss.
