I mean with export a “100% copy” of the dashboard HTML, together with “embedded data” or same-directory-json/csv-data files (all in a zip file) so that i could copy that dashboard on a USB stick or attach it to an email or to host is on a “standalone” webserver (without database connection)?

I mean, i only need a freezed version of that dashboard (no live-data; no SQL query execution) - like a snapshot (not a screenshot). A static export/copy of a dashboard.

Is there such an zip-file export build-in or available by a plugin or helper tool?

(i am very new on redash)

You might want to try creating a public shareable link and use a 3rd party tool/service to download a static copy of it