But in the United States and Canada, speaking face to face with stewardesses/waiters generally does not require a title.

Say sorry or hi!

Then ask him/her directly.

take for example

Excuse me, can I have a glass of water?

Hello, miss, how long will it take us to land?

If it is a third person, it is generally called a flight attendant (male or female).

A stewardess is a woman's name. There are many male flight attendants on American-Canadian flights, so it is more polite to use flight attendants.

For example:

Passengers must obey the conductor's command on the plane.

I am a Canadian, and I used to be an English teacher.