Select the chosen CV Input in the Mod Matrix as source and Pitch as destination. Set Amount to 100%.
Go to Global>Settings>CV and set CV scale to about 2V (or less) which corresponds to the 2 Oct pitch amplitude in the mod matrix.
Each CV input can be individually scaled.
Press the encoder once or twice to do fine adjustment.

For the function of the “Gate In” no special setting must be made. However, the “Sequencer / Arp” mode must switched off. To do that go to Perform>Autoplay and there select Off.