This question has been answered so many times

Right click on the button or knob you want to automate, then select "Edit Events". You will now have an editor. Select a blank pattern and in the playlist, put on block on that pattern where you want the automation to start. Then draw in your changes in the event editor. Hit play and it will folow those changes. If you want to automate a non fruity plugin, then at the top left of the fruity wrapper there is a power plug button, click it and select "Browse Parameters", then find the one you want to automate and select "edit events" again