MacBook Pro won’t turn on after restore failure

You can not simply update MacOS in your troublesome Mac. That article indicates its firmware has lost its integrity, and you need to follow a more complex procedure, spelled out in a linked article:

How to revive or restore Mac firmware - Apple Support

if that is what you were attempting, be certain you have set up the cable connection EXACTLY as specified AND have done the steps required in EXACTLY the order specified in the article.

If no joy, you likely need a service appointment to set it right.

Be sure to connect it to the power adapter overnight, so that it might have enough of a trickle-charge to proceed. If it has a deeply discharged battery, they may not be able to help you right away.

in the US and in areas with Apple-owned Store, your appointment at an Apple-owned store for an evaluation is free, in warranty or out.

If you have only Apple-Authorized Service Providers, they may charge an evaluation fee for that evaluation, to keep you from consuming expensive technician time with frivolous issues.

In many areas, you can contact support and after trying a few things, they can send you a courier-packing box with a return label (often hidden under the address label) to send in your device for service.

Official Apple Support

That is not, strictly speaking, an error message.

It is a link to a help article.

If your Mac starts up to an exclamation point in a circle - Apple Support

If you do not have another Mac to use to restore that Mac's firmware, you will need to find a friend who does have one, or make a Genius Bar appointment at an Apple owned store.

Your appointment at an Apple-owned store is free, in warranty or out

the error message says your Mac could not be Revived.

it might be ask-le to be Restored, but that would reset it to factory-new conditions (all your files would no longer be present.)

if you have Trusted Backup, such as a recent Time Machine backup on an external drive, you can readily restore from your backups after and get back to where you were.

If you have no backups, this will be a very hard lesson.

[in my opinion] there is unlikely to be any additional "magic" that can be applied at the Genius Bar to resurrect your files, Your drive was/is encrypted, and without working firmware, the contents of the drive is unknowable.