For setting up SRAM AXS Eagle with an 11 speed cassette, the following parts are required, AXS shifter with the revised paddle, an XX1 derailleur (the spec level does not matter as there are practically only material changes), and an E13 11-speed cassette with 9 and 46T cogs. Because of this, you might have to reduce the size of your chainring (for instance from 32 to 30 teeth) in order to achieve a range similar to a 12-speed setup. As per the manufacturer's instructions, the derailleur should be installed according to bearer+20 X mark. Moreover, the limit adjustments should be set and the B adjust tool should be employed. For this setup, an 11 speed Shimano XTR XDR Dura-Ace chain is preferred.