I am not too familiar with Uipath on Studiox, but I looked it up briefly and saw it has a ‘Start Process’ activity which you can possibly use to run a knime workflow through command line. You will need to input a command for it to run which you can follow the thread below for insight on how to do that:
The most integrated/simple way to run a workflow automatically would be to upload it on the Business Hub and schedule it to be run whenever you like.