html select tag with links that works after clicking a button

I want a select tag , choose an option , click submit , and go to a certain link . i found some solutions in here but wasn't what i was looking for , for example , some used onchange on select tag but it goes to the link before clicking the button , i look for a solution with php or javascript (no jquery) . this is what i tried , i don't know if it's correct or not . Please help, Thank you.

<form>
    <select class="custom-select" id="select" >
      <option selected>Choose...</option>
      <option value="page1.php">1</option>
      <option value="page2.php">2</option>
      <option value="page3.php">3</option>
      <option value="page4.php">4</option>
    </select><br>
    <input class=" rech btn btn-outline-success btn-lg" type="submit" value="RECHERCHER" onClick="location=document.getElementById('select').value;"><br>
</form>