No, you don't need to specify something to perform Pos instead of PoW. The transaction type (0x0 Legacy) is an old transaction format that is still valid for new transactions on the Ethereum network.
Legacy Ethereum transactions will still work and be included in blocks, but they will not benefit directly from the new pricing system. This is due to the fact that upgrading from legacy transactions to new transactions results in the legacy transaction's gas_price entirely being consumed either by the base_fee_per_gas
and the priority_fee_per_gas
.
See: https://github.com/ethereum/EIPs/blob/master/EIPS/eip-1559.md