...
Ensure that TX and RX are swapped as per above
The baud rate typically needs to be within +- 5% of the original baud rate, otherwise it will be mismatched and you will be unable to read anything.
Always check the tolerances on the clock of your MCU before using it in an async protocol application. If you don’t you may end up falling for baud rate mismatch. Note that typically an internal oscillator won’t cut it.