In the Promotion Terms and Conditions under the section for Redemption it states:
After Participant enters the Coupon Code, Participant may be asked to download a product
verification tool to confirm that the Eligible AMD Product is installed in the Participant’s
Windows system. In this case, Eligible AMD Product(s) must be installed and detected using a
Windows operating system to complete the redemption verification process. If Participant has
installed an Eligible AMD Product but is unable to complete the redemption process, a ticket
may be entered through “Contact Support” on https://www.amdrewards.com/support.
Participant may be required to provide further documents to verify proof of purchase of
Eligible AMD Product(s).
So you could try to contact support and see if providing further documentation to verify proof of purchase is acceptable rather than running the verification tool.
Another option might be to have your friend who has the processor installed run the verification tool and claim the coupon code on your behalf.
Ryzen R7 5700X | B550 Gaming X | 2x16GB G.Skill 3600 | Radeon RX 7900XT
Ryzen R7 5700G | B550 Gaming X | 2x8GB G.Skill 4000 | Radeon Vega 8 IGP
Ryzen R5 5600 | B550 Gaming Edge | 4x8GB G.Skill 3600 | Radeon RX 6800XT