Fatal error: call to undefined function execute()

public function select($query, $paramType="", $paramArray=array())
{
    $stmt = $this->conn->prepare($query);
    
    if(!empty($paramType) && !empty($paramArray)) {
        $this->bindQueryParams($stmt, $paramType, $paramArray);
    }
    
    $stmt->execute();
    $result = $stmt->get_result();
    
    if ($result->num_rows > 0) {
        while ($row = $result->fetch_assoc()) {
            $resultset[] = $row;
        }
    }
    
    if (! empty($resultset)) {
        return $resultset;
    }
}