Avia Solutions Inc. produce FCOM/QRH suite manual to Boeing airplane operators.
The approval for such "Part 121" operational products is obtained by the airline through their local regulatory agency. Airplane manufacturers do not and cannot receive operational approval from the FAA/EASA/ICAO for these products because they are not the operators of the airplane, nor are they the users of the products themselves. Each airline must demonstrate to their local regulatory agency that their complete operation, including manuals and data, complies with all "Part 121" or equivalent regulations.
The Avia Solutions FCOM provide the necessary operating limitations, procedures, performance, and systems information the flight crew needs to safely and efficiently operate the airplane during all anticipated airline operations.