i cannot select from two tables but i have the right code here it is:

$sql = "INSERT INTO ticket (senderName, receiverName, `Date`, ticketID, match1, match2, match3, match4, match5, match6, match7, match8, match9, match10, match11, match12, match13, match14, match15, match16, tip1, tip2, tip3, tip4, tip5, tip6, tip7, tip8, tip9, tip10, tip11, tip12, tip13, tip14, tip15, tip16, Bet, Gain, Odd) 
SELECT Username, '".$ticketReceiver."', `Date`, ticket_id, match1, match2, match3, match4, match5, match6, match7, match8, match9, match10, match11, match12, match13, match14, match15, match16, tip1, tip2, tip3, tip4, tip5, tip6, tip7, tip8, tip9, tip10, tip11, tip12, tip13, tip14, tip15, tip16, Uplata, Dobivka, Odds FROM kladilnica, users WHERE kladilnica.ticket_id='".$ticketID."' AND users.Username='".$ticketReceiver."'";

it gives me this error
Fatal error: Wrong SQL: INSERT INTO ticket (senderName, receiverName,Date, ticketID, match1, match2, match3, match4, match5, match6, match7, match8, match9, match10, match11, match12, match13, match14, match15, match16, tip1, tip2, tip3, tip4, tip5, tip6, tip7, tip8, tip9, tip10, tip11, tip12, tip13, tip14, tip15, tip16, Bet, Gain, Odd) SELECT Username, 'VladoRafa',Date, ticket_id, match1, match2, match3, match4, match5, match6, match7, match8, match9, match10, match11, match12, match13, match14, match15, match16, tip1, tip2, tip3, tip4, tip5, tip6, tip7, tip8, tip9, tip10, tip11, tip12, tip13, tip14, tip15, tip16, Uplata, Dobivka, Odds FROM kladilnica, users WHERE kladilnica.ticket_id='550415' AND users.Username='VladoRafa' Error: Column 'Username' in field list is ambiguous in C:\xampp\htdocs\asdf\navigation.php on line 217
and the line 217 is this one

$result = $conn->query($sql);
if($result === false) {
    trigger_error('Wrong SQL: ' . $sql . ' Error: ' . $conn->error, E_USER_ERROR); // <--- this one 
} else {...

please help

are you trying to insert into the database with the select statement or ...?

read the full question and code...

Error: Column 'Username' in field list is ambiguous

Username appears in both tables, you need to specify which one to use by prefixing the table name.