php fatal erro mysqli_connect() [duplicate]

<?php
    $servername = "localhost";
    $username = "root";
    $password = "123456";
    $dbname = "buke";
    
    $conn = mysqli_connect($servername, $username, $password, $dbname);
    $sql ="INSERT INTO xuesheng (xingming,nianling,xingbie) 
    VALUES ('小明','18','男')";
    
    if (mysqli_query($conn, $sql)) {
        echo "新记录插入成功";
    } else {
        echo "Error: " . $sql . "<br>" . mysqli_error($conn);
    }
    
    mysqli_close($conn);
?>

when i run it in visule studio 2019 ,I met :

Fatal error: Uncaught Error: Call to undefined function mysqli_connect() in D:codenodejshtdocsaddStudent.php:8
Stack trace:
#0 {main}
  thrown in D:codenodejshtdocsaddStudent.php on line 8

I have installed
php debug
xdebug
php intelephense
php intellisense

and edit the php.ini:

extension="D:phpstudy_proExtensionsphpphp7.3.4ntsextphp_mysqli.dll"
extension_dir="D:phpstudy_proExtensionsphpphp7.3.4ntsext"