How can I sign PSBT without an HD-Wallet?

[ShookLyngs]

Hi,I noticed that the library provides bip32 related features for HD derivation and signing. However, if I don’t want to use an HD wallet, can I sign PSBTs with just regular private keys, without injecting the bip32 related fingerprint, path, and other details to the target PSBTs?

Thanks.

[bsz0206]

I have the same issue. I need to sign using BIP84 and witness.