Set Key01 write node channels to default to rgba

Hi all,
I cant seem to find a proper setup to create write node with rgba channel’s default (so Key01 would include alpha channel).
My understanding was to under Create Write Prerender I need to create Write node exposed Knobs (where I typed) channels and then press plus once more and write rgba…obiously this is not working and I couldn’t find a document that describes something similar…so help please :slight_smile: