Why he will not load the function? and any question to Checkout Form

[MrVapor]

Hello,

Why he not call the function? 
 

<a href="clientarea.php?action=productdetails&id={$serviceid}&modop=custom&a=bckrestore&do&vserverID={$backup->vserver}&backupID={$backup->id}"
   type="button" class="btn btn-warning btn-sm">Wiederherstellen</a>
<a href="clientarea.php?action=productdetails&id={$serviceid}&modop=custom&a=bckdelete&do&backupID={$backup->id}"
   type="button" class="btn btn-danger btn-sm">Löschen</a>

and
 

I have found the module "Zur Kasse Formular" but i would like to do it myself because i don't see any money to pay for it, neither monthly nor yearly. (One time costs would be ok).

Then I looked at the checkout.tpl and found the TOS checkbox. So if I now add checkboxes. Where can I intercept data to save them because even the action url of the form is not worth the trouble.

Anybody got any ideas?

CU
MrVapor