BSC-chain is (almost) exactly the same as ETH, and I think my verification problem has little to do with the difference of the chains, I guess several things lead to my failure:
I don’t know how to find the corresponding code of AdminUpgradeabilityProxy and ProxyAdmin to different versions of @openzeppelin/hardhat-upgrades, I tried the master code of the openzeppelin-upgrades repo and the latest version of @openzeppelin/hardhat-upgrades(1.7.0), but still failed.
I don’t know how&where to get the Constructor Arguments for the AdminUpgradeabilityProxy.
It would really help if the verification process can be documented more clearly, thanks.