How to have multiple users in a user reference field I'm using Drupal 8.

Can I have multiple users by comma separating each users? When I was doing by this way, after I input a comma, I can choose another user again. But after I submit it. Only the last user I have chose that had been saved (only 1 value).

If I set the field as "Allowed number of values to Unlimit or a number". There will be many user reference text box. I only want one user reference text box and have multiple users with comma separating. How to do it?
Yes, you can do that.
You need to select "Autocomplete (Tags style)" as the widget you use in the Form display.



After you have done that, you can use commas to add multiple users in the same widget (provided you have set cardinality to > 1).