Mac desktop Terminal is unresponsive to a command and password when trying to create a bootable flash drive.

I'm trying to make a bootable Sierra flash drive for a friend who's old Mac desktop is bricked. I have followed all the instructions for rebooting using PRAM/NVRAM, no luck. Tried Disk Utility to repair then tried to reinstall Sierra, all via Recovery Mode. Nothing would happen, but if I rebooted and chose install again, it would advance to the Welcome page, then after a few frustrated restarts went as far as the install step ... then nothing. So, I'm hoping to use an external flash drive to try to repair it. But ...

I have downloaded the .dmg folder and now have the Install macOS Sierra.app in my Applications Folder on my desktop running Monterey 12.6.1. The Sierra file is 5.03GB. I have a PNY 32GB flash drive plugged directly into my HD. I have, through Disk Utility, erased it, formatted it to Mac OS Extended (Journaled). The name is sierrainstall.

The Terminal command I have been using (this among many others I tried) is:

sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/sierrainstall --applicationpath /Applications/Install/ macOS/ Sierra.app

sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/sierrainstall --applicationpath /Applications/Install\ macOS\ Sierra.app --nointeraction

sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/sierrainstall --applicationpath /Applications/Install\ macOS\ Sierra.app --nointeraction &&say

I have had returns such as:

command not found on createinstallmedia

You must specify both the volume and install application path.

I have run scripts to see if Terminal is busy in the background, since I've been going at this for days!

I have checked the file through Pacifist and the download is Signed. Package contents appear to be all there.

I can type in a command, it will ask for Password but not display my typing it, then nothing. If I tab down, the cursor is just blank as it moves down.

I have logged out and logged in with another Login and Password. Same result. I have run First Aid on everything via Recovery.

I ran the command on Terminal and then went into Activity Monitor. There was no activity with Terminal but pages and pages of createinstallmedia processes. It has Activity Monitor spinning and crashing. If I don't Force Quit, it eventually crashes.

What a mess I've created here while trying to help someone else with a mess because now my desktop keeps crashing and restarting.

panic(cpu 2 caller 0xffffff80084d1d35): thread_call group 'user' reached max thread cap (500): active: 500, blocked: 0, idle: 0 @thread_call.c:409

Panicked task 0xffffff8697800670: 705 threads: pid 0: kernel_task

Backtrace (CPU 2), panicked thread: 0xffffff8b639eaaa0, Frame : Return Address

Guess it needs a rest.

So, can anyone help me with finishing the last step to creating the bootable flash drive.

And ... is it likely rebooting from the flash drive will allow me to repair a bricked Mac desktop?

I'd really appreciate any help.

Thanks.