I’m not sure I understand the principle of putting a checkbox in a list.
If this is to select all default item, you may use the lists multipe with the selected
option on the option tags
<select multiple size="10">
...
<option selected="selected" value="<?=$row['first_name']?>"><?=$row['last_name']?></option>
....
good luck 🙂
solved how to add checkbox in select option in php?