This button is on the top of databus.dbpedia.org , maybe it is not well phrased. We can add a yellow “Beta” marker. You are right to be confused, https://databus.dbpedia.org is always online and looks decent now, but it is far from finished.
See e.g. OIDC Form_Post Response where we link to the forum and the code, but the links are not well integrated yet. This message should explain some: Why we switched from email to the forum