What’s the command you type at the console, and where is the executable located? Once you have this info, all you usually need to do is edit the file /etc/rc.localand place it before the exit command. Make sure you end the command you add with an ampersand(&) to make sure that it runs in the background.
For example, if you’re command is “discord somearghere” and your executable is located in /opt/discord/bin/discord, insert the following in /etc/rc.local

    /opt/discord/bin/discord somearghere &