Encode and modulate a test message on GNU Radio 3.8

[Rodrigo Ruiz]

Hello, I want to create a flowgraph in order to send a "Hello World" using
my LimeSDR-Mini.
The thing is that I want to encode the "Hello World" using NRZ, Manchester,
etc coding techniques, but I don't know if this is possible. Also I would
like to modulate on FM, for example. But as the input from the WBFM
Transmit block is a float, I don't know if my File source block could be a
float or I should use a conversion block.
I hope someone can help, thanks in advance.