Attestation signing of AMSI plugin

Hello!

I have AMSI plugin which is simple dll signed with EV certificate. Is there any way to obtain WHQL signature on such dll which is obviously not a driver? How one could submit his .cab file to partner center and request signature for such binary? As far as I understand this is possible (some urls which state that plugins require whql signature: AMSI Provider in 19H1 whit enabled code integrity check, svchosts.exe mitigation option and so on, but I can’t find and post which clearify the process of obtaining WHQL signature.