Sound Blaster Audigy FX drivers are still on Creatives website, haven't been updated since 2015 but have Windows 11 listed as compatible so they should work.
Sound Blaster Audigy Fx Software Pack
File: SBAF_CD_L13_1_00_07.exe
72126a4fca33d903732c0ab0a0d546fdb1f9b705c0a94aadaf5e70fb13225a88