That's pretty much how it was done, but few wallets support building a new transaction.

"BTCPay Server and Sparrow Wallet are two wallets that can be used to create partially signed Bitcoin transactions (PSBTs).

Explanation

BTCPay Server:

1. Log in to BTCPay Server

2. Choose the store to send from

3. Select "Bitcoin" under "Wallets"

4. Click Send

5. Enter the destination Bitcoin address and amount

Sparrow Wallet:

1. Import the PSBT transaction

2. Sign the transaction

3. Broadcast the transaction

PSBTs are a Bitcoin standard that allows multiple parties to sign the same transaction without exposing their private keys. This is useful when multiple parties want to add inputs to the same transaction.

PSBTs are a data format that allows wallets and other tools to exchange information about a Bitcoin transaction and the signatures needed to complete it."