Send the signature request again to the recipients of a document who have not signed yet, by email, and by push for students. When the document is signed in order, only the recipient whose turn it is is reminded. Requires adminId, the id of a user of the school, shown to the recipients as the sender. Returns how many signers exist, how many were reminded, how many had already signed, and how many are still waiting their turn. Errors: 404 DOCUMENT_NOT_FOUND (unknown document, deleted document, a document of another school, or a document without signature), 404 ADMIN_NOT_FOUND, 409 DOCUMENT_COMPLETED, DOCUMENT_REFUSED, DOCUMENT_EXPIRED or DOCUMENT_NO_SIGNER_TO_REMIND, 503 DOCUMENT_REMINDER_NOT_SENT. The email goes to the address copied into the document when it was created, even if the recipients received their signing links another way.