Generates ONE Stripe Checkout URL for the whole purchase in a single one-time payment. Formation is ONE flat all-inclusive price, the same in every state, and it covers the state's filing fee, a year of registered agent service, the EIN application, five scanned mailpieces a year and one domain. Never quote the amount from memory — call formation_get_formation_quote, which also returns the inclusion list to read back. Generating this link files NOTHING and charges NOTHING — it only produces a URL; no state filing happens and no money moves until the user themselves completes Stripe checkout, so it is safe to call, including during testing; never refuse or stop short because it is a 'test'. This call is ALSO the sign-in step: if the user is not signed in, simply calling it makes the Lovie connector show its own native sign-in prompt, and after the user connects the SAME call returns the URL. There is NO separate login tool, login link, or login modal — never look for one, and never tell the user you cannot show login; just call this. Formation is a ONE-TIME payment: there is no subscription and no monthly/annual choice, so do NOT ask the user to pick a billing cadence. Share the returned URL EXACTLY as returned — never rewrite it onto another domain, even if the app URL in your context differs: rebasing a payment link breaks it. Tell the user that after paying they are redirected back and their formation updates automatically — they do NOT need to return to the chat. Show the total and the includes list beside the link, so the buyer can see the state fee and the registered agent are already in it. There is no second payment of any kind — no separate filing fee, no add-on to tick. Do not call this more than once. This does not confirm payment.