sarsenbaev
To lookup Users you must search their email address or name in the "Search by email, phone or name" box shown in your screenshot. This should show a typeahead list of Users. Once you see the User in the list click their name and it should autofill the User's information. If none of the above happens check your logs (general server logs, webserver error logs, PHP error logs, MySQL/MariaDB error logs, osTicket System Logs, Browser Console logs, etc.) for any related errors.
In order to change a User's phone number you can click on the User's name in the Ticket header, click the Edit button, and then update the needed information there. Or you can go to the User Directory, search for the User, click on the User, click on their name, and update the Phone Number there.
Cheers.
