Launch Electrum, create a new wallet, "Import Bitcoin addresses or private keys", paste in the recovered key.

If you just paste the raw key, Electrum uses a legacy format, and none of the transactions show up for that private key. Adding the "p2wpkh:" prefix to the key makes the transactions show up, but I realized that well after someone else claimed it.

I don't know if this is an Electrum thing, if this is considered general knowledge now for those who regularly use BTC, or if it's a quirk of how BTC has evolved.