Currently, the control panels need to be created for each synthesizer model individually, there are currently about 15 control panels and they are automatically available to you if your synthesizer has an existing control panel.
However, if the control panel does not exist yet, they can be created by Play-a-Synth. If you are interested in hosting a synthesizer that does not have a control panel, just let us know here, just add a message under this topic or on our Discord server: Play-a-Synth
You can also try to build the panel yourself, the web session has an input text box where you can enter the control panel, you can read about the structure of the panel (with an example panel) here: Web control panel structure. We will, however, need to add it manually to the synth model to have it available permanently, so contact us if you wish to share the control panel with us.