Where to Do Glucose Test for Gestational?

I'm looking to do the glucose test for gestational diabetes, but I’m not sure if LifeLabs offers it and what their requirements are. I tried calling, but it’s hard to get through to a person.

For those who’ve done this test in London, Ontario, where did you go? Any other locations besides LifeLabs that offer it? Also, do I need to book an appointment, or is it walk-in?

Appreciate any advice! Thanks!