Help my phone is stuck in the reboot phase and it keep repeating again and again

[DiamantMains]

The phone is stuck in the reboot phase, and it keeps repeating again and again. Can't turn the phone off and can't access Bixby. How do I fix this and what do I need to change to do so? And how do I access my data from the phone so that I can either transfer it or store it on a different phone?

[VerbumVeritum]

Try pressing all the buttons simultaneously for an extended period of time. Does this do anything? How about hold power and volume down?

[justjustinagain79]

Have you tried holding down all three side keys until it goes black? Try that reset.