If you have a local Apple repair shop, check to see whether they have the special Apple black box to connect the Logic Board's Lifeboat connector for attempting data recovery. If they have this device, then you can have them connect it to the Logic Board and perform a simple erase of the whole physical SSD using Disk Utility. Due to how SSDs & TRIM work, this will reset all of the SSD's blocks to zero or an indeterminate state making it impossible for anyone to recover any data. This will most likely work even if the Logic Board is bad as long as Disk Utility is able to see the SSD of the broken Mac. Unfortunately an Apple Store is unlikely to do this for you since they likely don't have this special Apple device since Apple does not offer data recovery options anymore. Not all Apple repair shops will have this device though.