How to install driver for samsung scx-4521f MacBook air macOS 15.2?

HP does not offer drivers for that printer for any version of macOS newer than macOS 10.9 Mavericks, which is over eleven years old. Scanning may well not be possible - even VueScan which supports thousands of scanners does not list support for that model - but for printing can try setting it up as a "generic" printer. But it may well not work, in which case you will need to get a newer printer.

Good luck.

As varjak paw already indicated, the Mac drivers from HP for the Samsung SCX-4521F seem to be for (Mac OS X 10.4 Tiger to) OS X 10.9 Mavericks only.

https://support.hp.com/us-en/drivers/selfservice/samsung-scx-4521-laser-multifunction-printer-series/16462424/model/19135313

The above HP drivers, or one of the drivers (for similar models) in the Samsung Printer Drivers v2.6 for OS X download from Apple, can possibly be used with a few newer operating systems as well, but one should not expect installation under macOS Sequoia 15 to work. That would be entirely experimental.

Linux drivers are available for the SCX-4521F and other Samsung models.

A workaround involving an inexpensive Linux-based Raspberry Pi print server has been described for other printers. See, for instance, the posts by Techguyuk about a Kyocera laser printer in Can’t print with iPadOS17 - Apple Community. Tesserax reported about using a Raspberry Pi 3 Model B+ for an old HP LaserJet printer in Can I connect my laser printer to my netw… - Apple Community. The idea here would be to investigate whether a USB-connected SCX-4521F could be shared with a Mac in an AirPrint-like way on a network (thus not needing Mac printer drivers). Also experimental.