REGEX for multiple email address

[MAM78]

I would like to see an adaptive card created with an input text field that must be able to contain several email addresses.

I want to control the formatting of these email addresses with a separator ";".

I found a REGEX that matches the input format control here : https://stackoverflow.com/questions/9809357/regex-for-validating-multiple-e-mail-addresses

REGEX exemple 1 = "^([\w+-.%]+@[\w-.]+.[A-Za-z]{2,4};?)+$"
REGEX exemple 2 = "^(|([a-zA-Z0-9_-.]+)@([a-zA-Z0-9_-.]+).([a-zA-Z]{2,5}){1,25})+(;.+)*$"

But that doesn't seem to be accepted. Could you explain to me why?

What would be the correct REGEX format to use?