Select the "Bitcoin" icon on the bottom-right of the interface within the Cash App.
Tap the Airplane button
Enter the amount you wish to send and then select "Send".
Enter the recipient's wallet address in the "To" section. This can be done quickly if you copy/paste the wallet address. In this case, you'll find the wallet address that you're "sending to" on the deposit page . Select the address for the checkmark to appear to the right of it. Select "Next".
Enter your Cash App pin code. Select the withdrawal speed you would like to use. The faster the withdrawal, the higher the fee. Select "Next".
Confirm your withdrawal. Select "Done".
The minimum amount for a standard withdrawal (no fee) is 0.001 BTC or 100,000 sats (Satoshis).