After clicking Add an Optimal Feature, Add Windows Fax and Scan is not an option.
Yes, you are correct that the option is not there.
In Windows 11 Pro 23H2 go to:
Settings ==> Bluetooth & devices ==> Printers & scanners ==> Fax ==> Open print queue
That will bring up the "Windows Fax and Scan" app.
But it will not send a fax until you install a driver for your Fax modem.
I have a U.S Robotics PCI internal modem.
I did a clean install of Windows 11 Pro. Device Manager shows:

But Windows 10 shows:

Widows 11 appears to have no modem drivers,
so, I went back to Windows 10 to find what I needed.
Drivers are found here: C:\Windows\System32\DriverStore\FileRepository
It took some searching, but I finally found the driver in folder:
5638x64.inf_amd64_47f4dbbd80ecadd0
I copied this folder into my windows 11 Downloads folder
Back to device Manager ==> Modem ==> Update Driver ==> Browse my computer for drivers
Browse to the Windows 10 folder that you put in Windows 11 Downloads ==> Next
You will see "Installing Driver" and then "Windows successfully updated your driver"
Now you can actually send a Fax.
I have uploaded the driver to my OneDrive and here is the link:
https://sru365edu-my.sharepoint.com/:f:/g/personal/francis_hensler_sru_edu/EnQq9ScUhPRDqTqlp6RPkmsBrtzVdnuqUseHQ8aDWAjSTg?e=BgyojM