Change of activities (Änderung von Aktivitäten)

I want to change the activity type across multiple activities at once, but I can't find a solution.

(Ich möchte die Art der Aktivität über mehrere Aktivitäten auf einmal ändern, finde aber keine Lösung.)

I made a script to do this:

It runs in your web browser (like Chrome, Firefox or Safari).

You can use it to select activities via various filters (like dates, activity type, activity name, device ID), and change all of them to a new type.