In the root folder of the file you’ll find a sendmail.php file. This file takes care of the contact form from the contact us page. Even if the verifications of the form is made by js, this file will not work if you are not uploading it on your server. It needs the PHP server from your host in order to run.
You need to change 2 things before you upload it on your server: the name of your blog, and the email you want the contact form to be sent to. To do this modifications, open the sendmail.php and edit lines 5 and 6 from the file.
If you want to add another input field in the html file, you don’t need to edit the sendmail.php at all, just open the html page where the form is, add another input and if you want that input to be a mandatory field, you have to add the css=”required”. Note that this new input has to have name=”[example]“ and id=”[example]“