i can not send any email from the website that i programmed

i used a simple input form
if i try to open the /mail.php site on the browser, it shows me a blank page with nothing in it.input-form

Please Help, i just need to send out an email!!!!

Normaly it should send an email with the data that got wrote down on the input form directly to the email recipiant.
i tried it multiple times on my local host and it worked (i used composer).
overall files
php mailer file

if there is any (usefull) video on the internet, than please send it to me!!