Hi Christine. The Occupation sticker does not categorise, and is very flexible. The description says:
This sticker is used to note a person's occupation (career, profession or professional organizational affiliation) that was either important to them, or may have been a distinguishing feature about their life.
While being a hero is not usually a full-time occupation, it is certainly a distinguishing feature about a person's life, in particular for the case of Narcisse Lamontagne.
How about something like this?
{{Occupation
|image=AppropriateImage-123.png
|text=heroically saved eight children from a sinking ship.
}}
You might like to find an appropriate image, though an image is not mandatory.