How to set rgb_command_template

Hello,

I need to send the RGB set value command, for a MQTT light in the form:

string-oneR_COLORstring-twoG_COLORstring-threeB_COLOR

for example, for color 35, 40, 100:

string-one35string-two40string-three100

If I understand correctly, I have to set this syntax in rgb_command_template

rgb_command_template: “…”

How can I do that? I can’t find any example/doc…

thanks