Hi @lwadz88,
Following on from Ethan’s reply, another solution is to allow Sonic Pi to integrate with pulseaudio by making adjustments to one of the files scynthexternal.rb. I have described how this can be done in this post which explains what needs to be done. The advantage is that you can then right click the volume control icon on the taskbar and switch between any of the output audio devices available on your particular raspberry pi including any plugged in usb cards. I find that this simple card gives very reasonable results.
The above technique is convenient but you will get lower latency with another alternative, which is to enable QjackCtl in the Sound Section of the Main Menu which you can do using the Main Menu->Preferences->Main Menu Editor. `You can then start this program BEFORE launching Sonic Pi and set it up to use the sound output you wish. I did a rather sketchy run of this two years ago and sections of this thread give further ideas. Note this technique will take over the output audio device that you select whilst qjackctl is running, whereas the pulseaudio route enables programs to share your output device. If you make the modifications to scsynthexternal.rb you can then use either method.