The examples in this documentation assume that you are using a bundler with a tree shaking function (Officially supported are webpack and rollup). If you don't use such a bundler, you should not use the package @dicebear/collection, because it contains all official avatar styles, which would bloat your frontend.
Instead, you should use the packages for the individual avatar styles. For example, if you want to use the avatar style lorelei, you should install the package @dicebear/lorelei. You can find the package name for each avatar style in the documentation of each avatar style. Look for the section "Details".