Sorry about that. When overhauling OGS from version 5 to 6 a lot of thing in DataExplorer were disabled. Most are available again, but creating processes unfortunately still isn’t, as it is working fundamentally different than it used to.
As far as I know, you have to specify the process in the project file directly. You best option is probably checking examples of project files from the benchmarks to get an idea what the syntax looks like.
You could also take a look at our tutorial page if you can find something relevant to what you want to do (note that the Hydrology I tutorial is also outdated at this point).
I hope that helps a little.