The only way to recover the data if you don’t have a backup is to fix the board “enough” to get it to boot and be recognized by iTunes. Depending on the level of damage, this may or may not be possible however the only way to know is to send it to a repair shop that does micro-soldering/data recovery repairs.
Look locally for a reputable shop. Ideally, you want to find someone local but experience/workmanship trumps locality. There are many shops worldwide that do this so you shouldn't have any problems finding them. Talk to them and ask how they do their work.
If you can't find one locally, then consider mail-in repair. There are several reputable micro-solderers patrolling this forum. You can also click on my profile to learn more about my services, at the very least, it can serve as a data point.