Validation doesn't work

Like in the thread subject, I have an issue where if the first field is empty and then I click the submit button, it should show "is-invalid" class from bootstrap. But, I don't know why but in my case, "is-invalid" doesn't appear. To reconstruct it is in the video below, and the code is in the link provided. I'm using CodeIgniter v4.4.5

Code:
Comic.php: https://srcb.in/WpK36Jtntv
create.php: https://srcb.in/2bQAvdBdeG
BaseController.php: https://srcb.in/SzAbQ0mhtm
Routes.php: https://srcb.in/7xD5kTzVqt

Video tutorial + what I expected to be: https://youtu.be/IfMWgZf-To0?t=773

Video:
[Video: https://youtu.be/CshKImwRrcI]