hinge sensor liquid damage

The Lid Angle Sensor is replaceable! It can be ordered directly from Apple these days as they are now suppling parts and access to the needed calibration tool. You'll find the online manual here: MacBook Pro (14-inch, 2021) Repair Manual and here is the part: Lid Angle Sensor P/N 661-23649

Then Order the part via the online store here: Apple Self Service Repair Store

If you live outside of of the countries Apple is presently supporting, you'll need to contact a friend who lives in the covered area or a freight forwarder to act as your go-between. You will likely need a VPN connection to gain access to the paywalled tool as well.

The other option is locating a USED part as it will have already been programed unlike a virgin part now that you have the P/N it should be easier to find but given the systems age it won't be an easy part to find yet in the used marketplace.

Lastly review the iFixit guide here Steps 33 & 34 MacBook Pro 14インチ 2021 スクリーンの交換