Requesting to reschedule appointment with IRCC for PR

[Nick_150]

I got flight tickets for a trip before getting DM for permanent residency application which I received May 14 ,and from what I heard is that you receive the PR interview in about a month after receiving DM and that might be when I am gonna be out of country. Would be hard to receive a new appointment after request to reschedule ? and what are the risks ?
Thank you in advance .