There are a few ways to share a Padlet, found within the Share options in the top right corner of your creation. The easiest way is to grab a web link to your Padlet and copy/paste it to whoever you want to send it to (they can even still see it if the Padlet is set to Secret so long as they have the right link!).

Padlet share icon highlighted from the top right-hand corner of a padlet.
Padlet share options menu with the copy link to clipboard option highlighted.