iPhone unavailable after LCD replacement

Hopefully you made backups, once your phone becomes unavailable, your data on the phone is gone.

You can restore your data from a backup once you have reset the phone.

If you forgot the passcode on your iPhone, or your iPhone is disabled or unavailable -

Click on the link for instructions on how to reset your passcode without a computer if you have iOS 15.2 or higher.

If you see an iPhone, iPad, or Apple Vision Pro unavailable message or Security Lockout screen - Apple Support

Click on the link for instructions on how to reset your passcode using a computer.

If you forgot your iPhone passcode or your iPhone is disabled - Apple Support

I believe that Self Service became available with the iPhone 12 and above.

An XS Max would not have qualified for genuine Apple parts under the self service program, so it is very likely that the screen was a third party product.

Unfortunately, Apple Support and Service is probably not going to even look at the phone at this point, so service will have to be performed by a third party shop.

Upon review, my initial reply omitted the reasons behind the post.

Regret any confusion caused.

To restate:

There is a possibility that you’ll not regain access to your device; to include any data which might be currently on the device.

If so - while it’s unfortunately too late to backup now - all is not necessarily “lost.”

Apple’s default iOS behavior automatically backs-up (and iCloud syncs) your phone to iCloud in commonly encountered situations.

It does this “in the background” without any action required on your part.

If this “background” function has executed normally, your phone may indeed be backed-up.

So … IF an automated backup has indeed occurred … and IF you indeed need a replacement phone …

… you can restore any backed-up data onto your replacement phone as explained here:

Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

,

You performed the replacement yourself? Did you use official Apple parts or third party parts? Sounds like you may have messed something in either the disassembly or reassembly of the device.

Once you obtain your replacement phone:

Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

I don't see any mention of a "replacement phone" in the information provided by the OP. Are you assuming that this will be the solution?

But, even if a replacement phone is determined as the solution for the damaged screen on the XS Max, the OP has told us that.....

"Can not use the iphone and have a lot of things in it."

This seems to imply that the OP does not have a backup, so if this is the case, restoring the replacement phone......or even the current phone if it can be repaired......with no backup available will be quite a challenge.

You have borked your phone and forfeited all rights to support or service from Apple. They won't touch it now that it's been tampered with.

Recycle it and buy a new phone. Any data on the phone that was not synced to the cloud, backed up, or stored elsewhere is gone. There is no getting it back.