求助！从英国飞加拿大机票必须要买旅游保险的问题

我是从伦敦飞，在canada affair上定的，当时也就图便宜
今天翻看寄过来的机票确认信件发现上面写着：
Travel insurance is a vital part of your holiday and it is a condition of booking with us that all passengers have comprehensive personal Travel insurance.
If you have taken advantage of our fantastic instant purchase fares it is even more important to have travel insurance from the moment you book, our travel insurance will cover youshould you need to cancel.

是不是所有在canada affair上买机票的都要提供旅游保险，没有这个是不是不让上飞机啊？