Appear in court
Go to the courtroom at the courthouse on the day you were told to appear.
Because you haven’t served your former spouse, they won’t be present or represented at the hearing. A judge or master will hear your side of the story and make a provisional variation order based on the facts you’ve presented. The order won’t have any legal effect or be enforceable until it's confirmed (made final) by the superior court in the province or territory where your former spouse currently lives (BC or elsewhere).
The judge or master may expect you to have served your former spouse, so be prepared to refer them to section 18(2) of the Divorce Act. Tell the judge or master that you’re asking for a provisional variation order. Note that they may still require you to serve your former spouse before proceeding.