When is the best time to buy Camila Cabello concert ticket?

I have plenty websites where you can buy tickets for Camila Cabello concert but, I will suggest the best one among all it's eTickets. I usually buy tickets from this website and according to me, it is the best place to buy tickets not only for Camila Cabello concert but for other concerts too. I live in Canada and I was looking for her concert tickets too.