This is not a problem! You may have forgotten to flick the ‘toggle’ to share, on the pop up when you initially copied the link.
To check this, go to your Team Board.
Click the blue 'Share' button on the top right-hand side of the page.
Ensure you've moved the toggle to 'Enable sharing on this team.'
Then, 'Copy Link' and you're all set to share it.
If you are still having problems, please connect with the Beamible support crew via the chat function in the bottom right-hand corner of the app.