Greetings,
Welcome to the forum.
I am not a HP employee.
Please provide your PC's product number only.
I can't answer your question without checking the specs. I have not seen any HP PC's running Crossfire or SLI. It may be supported (I have never seen a HP consumer PC dual graphics card configuration).
HP does not provide much documentation on this subject.
A couple of questions:
Did the your PC's purchase specs indicate SLI ready or capable?
How many watts on the PSU?
Do you have two or more PCIe x16 slots on the motherboard?
Did HP include a SLI bridge in the box? SLI is licensed by Nvidia and adds costs to the motherboard. Crossfire is cooked and does not support DirectX 12.
Regards