Q. How is a hyperlink cited in APA?

Normally I would not think you would cite a hyperlink. A hyperlink is a vehicle that takes you to a source, and that source is what you are citing.

If you are citing a statistic from the National Library of Medicine, your source in the NLM, not nlm.gov

The hyperlink would be part of the citation, usually the last section, which allows your read to find the source. If the hyperlink is coming out of an ebook, use the URL of the source the hyperlink takes you to as part of the reference. Your reader might not have access to the hyperlink, but should have access to the source it takes them to.

If I am not understanding your question correctly, you will need to send more details.