TYPESCRIPT

mysqli_select_db expects 2 parameters

//do the correction as below:

$conn = mysqli_connect('localhost', 'root', '');
//the first thing that you have to pass connection variable in the select_db as first parameter. as below.

mysqli_select_db($conn,'altislife-dev');
//also you have to pass connection variable in mysqli_query() as first parameter as given below.

$records=mysqli_query($conn,$sql);