In this video you will see the usage of PSBT, watch-only wallets. And how to send transactions offline with your Coldcard and Bluewallet.
Using a Lightning to SD adaptor:
- Start the Coldcard device, go to Advanced → MicroSD Card → Export Wallet → Electrum Wallet. Put the SD card into Coldcard. Choose Native Segwit. It should create the wallet skeleton file on SD card.
- Put the SD card into the adaptor, go to the import wallets screen and choose your file.
- Create a transaction from this watch-only wallet, when prompted - export it to a file and save it in your folder.
- Put the SD card into the Coldcard, go to "Ready To Sign" and proceed with signing the transaction.
- Put the SD card into the adaptor. There should be 2 new files: - a file with the transaction hex that is ready to broadcast (*-final.txn),- a signed transaction file (*-signed.psbt).
- Choose the signed transaction file (*-signed.psbt).
- Tap send! You are done :)