Hi,

You can refer to Select2 Docs to populate Select2 dynamically.

You can run your code after the core-js includes in the html within the document ready event in order to access the core plugins and components once they are loaded and ready:

Then recompile your assets folder with Gulp.

Please note that the build tools are required only in the development environment just to compile the assets when the source folder files are modified. In the hosting/server deployment, you will only need the compile assets, no need to install the build tools dependencies there.

Regards.