The methods in which you’ll be able to spend a UTXO are restricted to what its output script permits, constructions out there for different forms of scripts are usually not transferable. So no, you’ll be able to’t spend a P2PKH UTXO utilizing P2TR guidelines.
In case you’ve heard about “wrapping” P2PKH in P2SH, which may imply utilizing the P2PKH script (OP_DUP OP_HASH160 <public_key_hash> OP_EQUALVERIFY OP_CHECKSIG) as a P2SH redeem script as a substitute of a naked output script (instance transaction). That is doable, however not helpful, since there is no purpose to hash the important thing and never use it immediately. You are able to do the identical with script-path P2TR (instance transaction), however once more, not helpful.
