Unable to install MacBook Pro Flash Storage Firmware Update 1.0 on Monterey

I just (2023) purchased a used mid-2015 MacBook Pro 15" laptop with Monterey installed. Software Update indicated that  "MacBook Pro Flash Storage Firmware Update 1.0" needed to be installed, but there was an error installing it and the prompt wouldn't go away. I was able to get the installation to work (and the prompt to disappear) following steps found on multiple apple sites, so I wanted to summarize it here.

Steps:

1. I used Disk Utility to add a 30 GB partition to my SSD. Call it "Old OSX." One must choose the (OS X Extended (Journaled) format for the partition as it is required for El Capitan. My laptop had been erased so I didn't need to worry about losing data. The existing Monterey system was kept in the existing partition.
2. I used Internet Recovery (Shift-Option-Command-R held down while powering up, until the initial grey wifi screen appears) to install the initial El Capitan operating system into the new partition (you'll need to select this disc for the installation -- it may be the only disc that appears as an option).
3. Restart the system, holding down the Option key until you get a choice of which partition you want to boot into. Choose the "Old OSX" partition. The MacBook will now boot into El Capitan.
4. You might be able to use Software Update directly now, but I used Terminal. Open up Terminal in the Utilities folder. In the command line in Terminal, enter the command:

softwareupdate -l

There will then be a list of software update packages you can install. You only want the package for the Flash Storage. Then type the command

softwareupdate -i NAME

where NAME is the specific name of the Flash Storage Update copied from the list you see on Terminal. You may have to use a sudo command and enter your password. Hopefully, the installation goes fine and you'll receive an installation done message without the error that appears if you tried doing this in Terminal when running Monterey.

You'll now need to restart the computer. For me, upon restart, the computer showed a picture of a flash drive initially, then after a short pause, restarted as normal. I was then in the El Capitan partition.

1. I then restarted the laptop again, holding down the Option key, and chose the Monterey partition. Once the computer was restarted, the Software Update prompt for the Flash Storage Update was now gone. Software Update indicated that my system was completely up to date. I then went into Disk Utility, and deleted the "Old OSX" partition. I restarted the computer again, and I was back in the situation I started with, but with the Flash Storage Update installed, as desired!!!