Anthony Towns shared that Taproot is activated on Testnet.
I am not sure if we can create P2TR outputs easily on Testnet right now based on this Q&A by Michael Folkson:
How can I spend from a P2TR address on Signet with the Bitcoin Core wallet in 22.0?
I am interested in reviewing PR: https://github.com/bitcoin/bitcoin/pull/22421 and test utxoupdatepsbt
on Testnet with PSBT spending Taproot outputs.
tr(xprv/*)
for some xprv. See github.com/bitcoin/bitcoin/blob/master/doc/descriptors.md for more advanced ones.