How to save the entered values ​​in the fields if the page is reloaded?

Question

PHP

I tried to use input value S_POST in the fields, but apparently I'm not using it correctly, or something else.
I tried it through a script, it saves sisyphus.min.js, but saves the entire form, and I don’t need to save all the fields in the form.
Suggest a solution.

<form name="add_my_ankete" id="add_my_ankete" 
action="/personal/order/make/process.php" method="POST" 
enctype="multipart/form-data">
<input id="fullname" name="ORDER_PROP_1"
 type="text"  required="required" 
placeholder="Ф.И.О"
value=""/>

Answer 1

localStorage

Answer 2

cookies!?