Execute command without terminal output

If you don't need the output at all then redirect it to /dev/null

yourcommand > /dev/null 2>&1

otherwise you can redirect into a file:

yourcommand > /somwhere/file 2>&1

And as you run the command from another application and you want use your news reader immediately you may want to run the command in the background. I am not sure how it works in this newsboat, but in a shell you can send programs into the backround with &

yourcommand > /somwhere/file 2>&1 &

To run command silently in background, which will "survive" even if terminal will be closed afterwards, use screen in detached mode:

screen -dm your_command(-s)

to reattach screen with the command running execute

screen -r

To detach reattached screen press CTRL+A+D.

Without screen you should execute your command with nohup, thus the process will run if the terminal is closed afterwards, like the screen utility:

nohup your_command(-s) &>/dev/null  &