1. Run Cashtab locally (npm start or equivalent).
2. Test the following transactions:
Authentication Tx:
https://cashtab.com/#/send?bip21=ecash:qrrn6yvaah3p4jjm8uwet935hdh7apufjc6m9w8prz?amount=5.5&op_return_raw=044e465400134c6f67696e20746f2047617564696f2041707008eb0c601b84975437
Regular Message Tx:
https://cashtab.com/#/send?bip21=ecash:qrrn6yvaah3p4jjm8uwet935hdh7apufjc6m9w8prz?amount=5.5&op_return_raw=044e4654001648656c6c6f20576f726c642066726f6d204e46546f6100