All code are beautifully written. You can customize easily. Just look the amex/typography.html file go to form code with change and use.you would like to edit a specific section of the site, simply find the appropriate label in the and change what you need.
amex bootstrap 4 admin dashboard provide this beautifull with standard typography form you can see this documentation
Custom typography
Hello Typography 1
Hello Typography 2
Hello Typography 3
Hello Typography 4
Hello Typography 5
Hello Typography 6
Bootstrap typography
Hello Typography 1
Hello Typography 2
Hello Typography 3
Hello Typography 4
Hello Typography 5
Hello Typography 6
Paragraph typography
Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.
Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.