Each "Page" in a Figma file is assigned a unique presentation URL by the Pitchdeck plugin, so updates made to the deck and re-uploaded within that page will update the presentation on that page's URL.

To have multiple URLs, creating a new "page" via the left hand column in Figma inside your file (or just creating a new Figma file) will create a brand new URL/password specific to that page once it's uploaded for the first time via the plugin.