How can you find a missing icon without changing your whole toolbar?

Search by the action, such as download, and check nearby icons from the same collection. Use a consistent outline or filled style at the size people will actually see. Keep an action label when a new symbol could be unclear.

Will the icon load without a separate service?

You can include a copied SVG, a scalable image described by shapes, or bundle selected icon data with your app. Some Iconify components can request icon data when the screen opens. That approach depends on the configured icon service responding.

Iconify documents a free public API and a self-hosted option. Hosting your own adds a service to maintain. For a small, known group of controls, compare that work with including just those icons in your build.

Which license applies to the icon you copied?

Read the license listed for that collection. Iconify’s code and tools have their own licenses, separate from the icon artwork. Save the collection name, icon name and applicable notices with the asset. If the collection requires credit, keep it in your handoff.

What should the control do if the icon never appears?

Sketch a fictional toolbar on paper. Draw a Download button and a second copy with the picture removed.

Read the button
Its wording should still explain what happens.
Check the second action
Give an icon-only button an accessible name that describes its action. Draw where focus would go on Tab. The sketch does not test an actual interface.