How to use prepared statement for separated mysql query

I am little confuse how to use prepare statement in this. i tried but failed as my query is separated.

$q = "SELECT * FROM report WHERE 1";

if(isset($_GET['name']) && !empty($_GET['name'])){

 $name = $_GET['name'];

 $q .= " AND user ='$name'";
}

if(isset($_GET['category']) && !empty($_GET['category'])){

 $category = $_GET['category'];

 $q .= " AND category ='$category'";        
}

$q .= " ORDER BY report.id desc LIMIT $offset, $no_of_records_per_page";
$all = $conn->query($q);

I have tried this but it messed up and dosenot work.

$q = $conn->prepare("SELECT * FROM report WHERE 1");

if(isset($_GET['name']) && !empty($_GET['name'])){

 $name = $_GET['name'];

 $q .= " AND user = ?";
}

if(isset($_GET['category']) && !empty($_GET['category'])){

 $category = $_GET['category'];

 $q .= " AND category = ?";        
}

$q .= " ORDER BY report.id desc LIMIT $offset, $no_of_records_per_page";
$q->bind_param('ss', $name, $category);
$q->execute();
$all = $q->get_result();

Here's how I'd code it using a prepared statement (using PDO):

$terms = [];
$params = [];

if($user = $_GET['name'] ?? null) {
  $terms[] = "user = ?";
  $params[] = $user;
}

if($category = $_GET['category'] ?? null) {
  $terms[] = "category = ?";
  $params[] = $category;
}

$where = '';

if ($terms) {
  $where = "WHERE " . implode(" AND ", $terms);
}

$q = "SELECT * FROM report $where 
  ORDER BY report.id desc 
  LIMIT $no_of_records_per_page OFFSET $offset";

$stmt = $conn->prepare($q);

$stmt->execute($params);

I assume $offset and $no_of_records_per_page are not from an unsafe source. If they are set using literals in your code, they're safe to use directly in the query.

Re your comment:

PHP's [] operator can add just one element to the array. If the thing you add is an array, that becomes a nested array.

You can append multiple elements to the array in a couple of ways. Either one at a time:

$params[] = $from_date;
$params[] = $to_date;

Or use builtin array functions, like either of these solutions:

$params = array_push($params, $from_date, $to_date);

$params = array_merge($params, [$from_date, $to_date]);

Or in PHP 7.4 and later, you can combine arrays this way:

$params = [...$params, $from_date, $to_date];