Unavailable iPhone 11 passcode reset with family account and no computer recognition

Hi! I have been letting my kid use my old iPhone 11 but the passcode was entered incorrectly too many times and is now in the "Unavailable" mode where it doesn't show any "try again" time period. He is under my family account, but I am not seeing a way to reset the passcode or reset the phone through mine. Also, quite an important piece of information- my computer doesn't recognize the phone when it's plugged in. It will recognize my current phone though, so I know it's not a cable issue. I assume it's because I am not able to unlock it and click the "trust this computer/device" option. The phone has no service, and it restarted due to being dead so therefore it's not connected to the internet at all. I have no idea what to do from here. Since the phone isn't able to be recognized by the computer, iTunes isn't showing the reset option. Any ideas on where to go from here? I have looked up numerous videos, but none help with this specific of an issue.

TLDR;

iPhone 11 needs unlocked

Account is part of a family account

Not connected to internet

Computer won't recognize phone

Not a cable issue

iTunes won't recognize phone

Unavailable, with no "try again" message.

Any advice is appreciated!

Side note: The nearest Apple store is in the next state over.. so that's not a viable option sadly.

[Re-Titled by Moderator]

Original Title: Locked iPhone, help!