Undefined method failValidationErrors (PHP version 8.0.5)

This error occurred when I used my laptop with PHP version 8.0.5
Note: This is working on other PC with PHP version 8.1
https://drive.google.com/file/d/1vbSQRrY...sp=sharing

Here's the snippet code:
https://drive.google.com/file/d/15ZTydUn...sp=sharing
https://drive.google.com/file/d/1NZneOl5...sp=sharing

Can I run this with my current installed PHP version 8.0.5 as I can't find any documentation that I am required to install latest PHP version.

CodeIgniter v4.2.0 works with PHP 7.4 or later.
See https://codeigniter4.github.io/CodeIgnit...highlights

P.S. I cannot see the images.

ci-phpunit-test | CodeIgniter Testing Guide | CodeIgniter 3 to 4 Upgrade Helper

CodeIgniter v4.2.0 works with PHP 7.4 or later.
See https://codeigniter4.github.io/CodeIgnit...highlights

P.S. I cannot see the images.

Since the images cannot load, I updated it to google drive links.
Anyway, I just updated my PHP version for it to work. Still, some may find this useful if there's a solution other than upgrading the PHP version.