Partner portal Onboarding Tracker Remind action. The onboarding app sends the entity's applicant its reminder email, whatever the partner's PartnerEmailsAccount setting. The entity must be in the partner's book, in Application Pending, and have an onboarding application: an entity that does not exist, one outside the book and one with no status get the same not-found error as the drawer, and one in another stage or without an application gets an invalid-action error. If the onboarding app cannot be reached or fails, the request fails with an integration error. Writes an account note (a partner note for a child partner) naming the portal user. Requires a partner portal session (bearer token) of an Admin user and the AccountOnboardingFormAccess permission; Viewer and Support users are rejected.