Step 3A. Companion mode (new browser window)
The objective
Launch Pad becomes a companion to your app: your user clicks "Plan this field" in your product and a new browser window opens straight on path planning for your boundary, already signed in as that user - the account step 2 created for them - with no Launch Pad sign-up, no login screen, no file upload. This page is just the last mile.
The moment your user sees
Your backend (still your Partner Admin service account) requests a
single-use launch code for the user who clicked - the one
provisioned in step 2 - and opens Launch Pad's /launch URL in a new
window; Launch Pad exchanges the code for that user's session, not
your service account's, and forwards to the boundary. Codes expire after 10 minutes
and die on first use, so a real integration requests one at click time - exactly
what this button does.
Prefer the iframe look instead? The same launch URL drives B. Embedded mode (iframe in your UI).