NLSdb query result

Fatal error: Uncaught Error: Call to undefined function mysqli_connect() in /mnt/project/nlsdb/public_html/nlsdb/databaseCon.php:2 Stack trace: #0 /mnt/project/nlsdb/public_html/nlsdb/browse.php(20): include() #1 {main} thrown in /mnt/project/nlsdb/public_html/nlsdb/databaseCon.php on line 2