Fire fbq event with user_data

Question

In FB doc, it is explained how to bind user_data to fbq while initializing fbq. However it is not explained how to bind user_data later on.

Let's say I have a form where users put their email. When the user hit "send" I call fbq("trackCustom", "my_event"), is there a way to make FB know customer's email so it can performed advanced matching?

I was thinking of maybe this:

fbq("trackCustom", "my_event", {user_data: {em: hash256("email")}})

Or this

fbq("setUserData", {em: hash256("email")});
fbq("trackCustom", "my_event");

But no way to find the right answer on Google.