Unable to drag and drop entities on Figma web via self-hosted UI

Hey, we recently launched a plugin for FigJam (https://www.figma.com/community/plugin/1220696620350131525) that exports notes as Stickies and clips as Embeds.
This works fine for Figma Desktop App but doesn’t replicate same behaviour on Figma on web. We have followed the official guide for implementing drag and drop for self-hosted UI.
Official Code Example:

We’re now left with the following doubts

  • Is it not possible to implement drag and drop for self-hosted UI on Figma Web? If yes, what else should we do to ensure the same?
  • Currently its not possible to test Figma plugins for web during development, could there be a way to test how plugins would function on web in the future? This would help us avoid unexpected behaviour after we launch or update the plugin.