This page tests various ways to dynamically load icons without API (except for first example that uses API).
On success, after each line of text there should be a green icon.

Icon loaded from API (should not load):

Icon loaded with addCollection():

Icon loaded with addIcon():

Icon loaded with IconifyPreload:

Icon loaded with addCollection() and custom provider:

Icon loaded with addIcon() and custom provider:

Icon loaded with IconifyPreload and custom provider: