(1)   If a variation of a cooperative workplace agreement is made as mentioned in section   216C, the employer must apply to the FWC for approval of the variation.

  (2)   The application must be accompanied by:

  (a)   a signed copy of the variation; and

  (b)   a copy of the agreement as proposed to be varied; and

  (c)   any declarations that are required by the procedural rules to accompany the application.

  (3)   The application must be made:

  (a)   within 14 days after the variation is made; or

  (b)   if in all the circumstances the FWC considers it fair to extend that period--within such further period as the FWC allows.