Yes, you must provide a certification, as required in § 301-10.142 and any other documents required by your agency. Your agency cannot pay your foreign air carrier fare if you do not provide the required certification.
Code of Federal Regulations
[FTR Amdt. 74, 63 FR 63419, Nov. 13, 1998, as amended by FTR Amdt. 108, 67 FR 57964, Sept. 13, 2002]