Send parameters through the URL after form submission - html

Question

I have a simple product selection form where user gets to select how many products to buy. Based on his selection, I would need to append the URL with his selection. If he selects Product1 and Product2 the submit button should add those two products to the cart with the following parameters https://example.com?add-to-cart=10,20
Here is example of my form
<form action="/action_page.php">
<input type="checkbox" id="10" name="vehicle1" value="Bike">
<label for="vehicle1"> Product 1</label><br>
<input type="checkbox" id="20" name="vehicle2" value="Car">
<label for="vehicle2"> Product 2</label><br>
<input type="checkbox" id="30" name="vehicle3" value="Boat">
<label for="vehicle3"> Product 3</label><br><br>
<input type="submit" value="Submit">
</form>
How can I achieve this?
Found something similar here but don't know how to modify it per my example.

Answer 1

This will redirect to example.com?add-to-cart=10,20
<script>
$('form').on('submit', function(e){
e.preventDefault();
let params = ''
const redirect_url = 'axample.com?add-to-cart'
let count = $('input[name^="vehicle"]:checked').length
$('input[name^="vehicle"]:checked').each(function(index) {
params += $(this).attr('id')
if(index !== count - 1) {
params += ','
}
});
// Amend redirect url in form by adding fields from form
window.location.href = redirect_url + '=' + params
});
<script>