You have not explained why you won’t attend yourself? But in any case, the age-old way of voting at an AGM if you cannot attend yourself is to appoint a proxy – which is another person who will attend in your stead. You will have been provided with the “Appointment of a Proxy” form with the AGM Agenda. It can be downloaded from the government Strata website too. Complete it, and submit it to the strata manager or secretary. You can appoint a friend to appear for you, or commonly, appoint another owner who is attending anyway. You can provide a list of votes for all the agenda items, as well, so the person you appoint votes as you want, or just give them your instructions about how to vote.
Keep in mind that you have to be financial (ie, your levies up to date) at the meeting, in order to vote.