Generates authorization URL for QuickBooks OAuth with tenant-scoped state. Both /api/v1/integrations/quickbooks/* and /api/v1/quickbooks/* map to the same ApiQuickBooksController method (initiateOAuth). This family uses route handlers that instantiate ApiQuickBooksController and usually wrap calls in explicit try/catch handleApiError blocks.
Content type: application/json · schema QuickBooksV1OAuthInitiateBody
Success response 200 · schema QuickBooksV1ApiSuccess