The purpose of the dashboard is to have it be a permanent display on a monitor in our office, opened on launch by a rasberry pi
That is why we cannot login.
I tried exporting the dashboard to PDF, but it spins forever without creating the pdf.
Keep your eye out for Splunk Developer Cloud, announced at .conf as one of the parts of 'Splunk Next', which allows you to build dashboards outside splunk, that are based on data from Splunk. See also some of the .conf sessions on this topic: https://conf.splunk.com/conf-online.html?search=developer%20cloud&search.event=conf18#/
If you want a dashboard with many panels, you will need to expose multiple reports and create a HTML page that embeds all of them.
Converting a dashboard to HTML will not help. You are exposing reports, not dashboards.
Beside the PDF delivery there is no way?
We want to show the dash on a special monitor to show stats in the office. but the monitor has no mouse or keyboard, so there is possibility to login.