Is this a 17R3 or an m17 R3? The AX201 card needs a CPU that supports CNVio -- which the one in the 17 R3 does not.  The m17 R3 will support that wireless card. The 17 R3 needs the AX200 card -- which is a conventional M.2 wireless card not requiring a CPU and chipset that support Intel CNVio.  
Can the Alienware 17 R3 Laptop's WiFi card be upgraded to WiFi 6 using the Dell AX201 card?
17 R3, WiFi 6 upgrade with Dell AX200/1?