Same extension, same license key, native Edge Add-ons install.
Open edge://extensions, open PDF Dark Mode Details, turn on Allow access to file URLs, then refresh the PDF tab.
Buy once ($9.99) and activate the same key in Chrome and Edge. If an activation is refused at the limit, email contact@pdf-dark.com.
Try it now: install from Edge Add-ons or use the free web reader. See also: Chrome guide, help page.