Read one sealed e-invoice by id, with its portal_field_sheet: the document's values laid out to key into the LHDN MyInvois portal form (e-invoice details, supplier, buyer, each line, totals), coded values with their meaning. Simpler never submits to LHDN; portal_field_sheet.portal_routes names the two portal routes (the online form and LHDN's Excel batch template). Refuses an id outside your tenant with NOT_FOUND: call myinvois_invoice_list for valid ids. NEXT: after the portal accepts it, myinvois_invoice_record_submission with the UUID it assigns.