This article will walk you through the steps of editing fields on the Contact Form.
1. Go to ap-admin -> Contact -> Contact Forms and click "edit"
2. You will see contact form fields and HTML structure
3. You can edit templates of your form and email using various types of tags (string enclosed in square brackets). Contact Form 7 provides two types of tags for the form and email templates: form-tags and mail-tags. The syntax of the two types is entirely different. For example, you use [text* your-name] in your form template and [your-name] in your email template.
4. Please check this article how to customize it, add new fields, etc: https://contactform7.com/tag-syntax/