Importing cards to one board

@Babak Sadighi - This is not currently possible using out-of-the-box Miro functionality.

A custom Web-plugin that also uses Miro’s REST API

What you have described should be possible to create a custom web-plugin using Miro’s Miro Developer Platform. You would probably want someone with a development background to review the developer platform documentation.

Suggest this as a feature by creating a Wish List Idea

I’d recommend adding this as an Idea in the Wish List category by following the guidelines here: Wish List: Everything You Need to Know.

If you do create a Wish List Idea post, I would also recommend that you post a link to it back here, so that future readers of this post can quickly get to and vote for your Idea.

Lastly, don't forget to vote for your own Idea.