CI4 and Bootstrap

My Assets library can help with this:
https://github.com/tattersoftware/codeigniter4-assets

Right now you need to setup each of the pieces, but the next major version will have built-in support for some of the major popular packages.

composer require tatter/assets
composer require twbs/bootstrap4

For an example of an automated version of this right now see:
https://github.com/tattersoftware/headquarters

Pay attention to composer.json, post-update.sh, app/Config/Assets.php, and app/Views/templates/header.php