Can I withdraw or leave my team after registering?

Yes — but only while registration is still open. Use Withdraw (or Leave team) on the tournament's page.

Once registration closes, none of it is possible any more: you cannot withdraw, you cannot leave your team, and a captain cannot remove a member. The bracket is seeded from the roster at that moment, so changing it afterwards would mean rewriting matches other people are already scheduled to play. Support cannot override this.

If you know you cannot make the dates, withdraw before the deadline rather than not turning up — a no-show is resolved as a loss and your opponent advances.