This guide details how to apply a Casa vault transaction signature using your YubiKey
Sending transactions
First, create a transaction as normal by tapping "Send" from your vault. Enter the amount you want to send, then enter the address you're sending to, just like any other transaction.
When you begin signing the transaction with your hardware device, click, "Tap to add new signature," then tap "Send Email" on the next screen.
Casa will send you an email with a subject like “Add the second signature for your 3-key vault transaction” (or “Add the second or third signature for your 5-key vault transaction”). This email will come from no-reply@mail.keys.casa.
Didn't get the email? See: How to sign with a hardware device without email access.
Click "Sign with Hardware device" in the email from your laptop or desktop computer, Then, follow the instructions in your web browser to sign using the YubiKey device.
Note: You should always use Chrome when signing with a YubiKey.
Tap on your YubiKey then enter your pin and then tap on the YubiKey again to confirm.
That's it you have successfully signed with your YubiKey!
Once you apply the signature from your YubiKey, you can go back to the mobile app, apply another signature if needed and tap Complete transaction so it broadcasts to the network.