It is a requirement for the Church that your former spouse be notified that the annulment process has started, so as to offer them the opportunity respond.
What you need to do is let the Church know where your ex-spouse currently stays. You do not have to have anything to do with them.
Your ex-spouse will be sent a letter explaining the process that was initiated. They do not have to agree to the annulment. Whether or not your ex-partner takes part in the process, the annulment will still go ahead regardless.
The problem is if you do not know the whereabouts of your ex-spouse, how can you possibly find out where they are?
Here are some great ways to find your ex-spouse.
While we are on the subject of marriage, annulment and ex-spouses, many people nowadays are attempting to save their relationships. There are many courses and programs online that can help. Two such programs are Relationship Recovery and Save My Marraige Today. You can read a full Relationship Recovery review and Save My Marriage Today review to decide whether they are for you or not.