The Zendesk help center provides end users with a default HTML form for submitting tickets:

It's a good starting point but it might not meet all your needs. Here are other
                        options, including:
Customizing the help center ticket form
You can add custom fields to the help center form or change its look and
                                feel. 
Note: If you have the Professional add-on or are on
                                        Enterprise, you can define multiple custom forms for
                                        different types of requests.
Resources:
Embedding a ticket form in your website
The embeddable Web Widget (Classic) includes a customizable HTML form that lets end users submit tickets. You can embed Web Widget (Classic) in any page of your website. Clicking the widget gives the user the option of using a ticket form:

Resources:
Building a ticket form
For maximum flexibility, you can build your own HTML ticket form, host it on your own server, and use the Zendesk API to submit the form data to your Zendesk Support account.
Important: If your team prefers to create
                                a custom ticket form, it is not recommended to route requests from
                                the form through a support email address. This workflow is
                                unsupported and can result in emails becoming suspended tickets. To
                                avoid this issue, use the API to build
                                your ticket form or utilize the Web Widget. See Tickets created from my
                                        custom ticket form are suspended.
Resources: