Here you can read the Q&A history.
To get new community support please go to GitHub discussions (KnowageLabs/Knowage-Server · Discussions · GitHub).
Dear Plotr,
you can create your own widget through Knowage source code, but you should refer to Knowage GitHub repositories (https://github.com/KnowageLabs).
Otherwise, in this moment within Knowage you must choose between the already provided widgets, that in Knowage 7.0 are the following: