Documentation from the Internet
Some websites sell certificates, registrations, and licensing documents for assistance animals to anyone who answers certain questions or participates in a short interview and pays a fee. Under the Fair Housing Act, a housing provider may request reliable documentation when an individual requesting a reasonable accommodation has a disability and disability-related need for an accommodation that are not obvious or otherwise known.35 In HUD’s experience, such documentation from the internet is not, by itself, sufficient to reliably establish that an individual has a non-observable disability or disability-related need for an assistance animal.
By contrast, many legitimate, licensed health care professionals deliver services remotely, including over the internet. One reliable form of documentation is a note from a person’s health care professional that confirms a person’s disability and/or need for an animal when the provider has personal knowledge of the individual.
https://www.hud.gov/sites/dfiles/PA/documents/HUDAsstAnimalNC1-28-2020.pdf (page 11)