my-projects-website/app/application/resources/site/js/_choose-documentation-version.js

let blockDocumentationVersion = document.querySelector('#documentation-version');
if (blockDocumentationVersion) {
    blockDocumentationVersion.querySelector('.documentation-version__button').addEventListener('click', (e) => {
        if (blockDocumentationVersion.classList.contains('active')) {
            blockDocumentationVersion.classList.remove('active');
        } else {
            blockDocumentationVersion.classList.add('active');
        }
    });
}