Using Envelopes to trigger STO

[XORadmin]

Exactly, the SOURCE defines where the envelope starts and stops. If you set it to Gate 1 for example , then it listens to the gate of track 1. Like when you play a note from track 1 then the gate is on and if there is no note then the gate is off. Gate On starts the envelope and gate off stops it. (In AD-SR Mode) Or just a gate on is enough to trigger the envelope.
You connect the envelope output (destination) with the CV input of the VCA. Then you could normally connect the output of the Oscillator into the input of the VCA. The output of the VCA is now your result letting the envelope controlling the volume of your oscillator within it's envelope shape.

NerdSEQ MOD -> VCA CV IN
Oscillator -> VCA In
VCA Out is the audio output you can use to listen to or for further processing.

Of course this is only one of the endless options. But thats the first simple patch. I suggest to check on your favourite video platform for some basic modular/eurorack patching videos to get a grip and understanding on that. And the NerdSEQ will take care for the sequences and modulations then :-)