Thank you for posting in the Intel Community.
I was looking into DELL™ reference link for the DELL™ Precision 5820 Tower Workstation (https://www.dell.com/en-us/work/shop/cty/precision-5820-tower-workstation/spd/precision-5820-worksta...) and they only recommend the Intel® Dual Band Wireless AC 8265.
Taking into consideration that these systems are prebuilt units it is important to confirm the hardware compatibility with them (https://www.dell.com/support/home/us/en/04).
Please keep in mind the regulatory information regarding wireless hardware installation or upgrade (https://www.intel.com/content/www/us/en/support/articles/000005687/network-and-i-o/wireless-networki...).
Intel Customer Support Technician