httpget() variable

hi profs can i ask for a help on how to input variable phone_number in httpget this is my line of code

inet.httpGET("mydatabasedomain.esy.es", 80, "/weblumenconnectiontoarduino.php?phone= phone_number ", msg, 250);

i expecting number from phone number variable but it sends the name of the variable in my database

sorry for my english