in zoom healthcare

I am a therapist and i send out a meeting invite to a couple - to each of their email adresses. When they come onto zoom i only see one of them at a time (when they are speaking). I need to see them both  at the same time - which is gallery view i believe. I do not see the option for gallery view.... I tried swiping to the left when i had one participant on as directed by a blog - that didn't seem to work. Any ideas?