Apple AX chipsets are soldered into the logic board, no cards that you can replace.
AX PCIe cards have no macOS drivers, when you install a PCIe card it usually works only with Linux or Windows.
Btw, even for the Wi-Fi 802.11ax chipsets that have open source drivers that work with macOS, like for some of the Intel AX chipsets, the performance is considerably inferior when compared with Apple Broadcom 802.11ac chipsets and the cards stop working after you enter sleep.
https://openintelwireless.github.io/
Forget 802.11ax compatible cards and macOS.