Prompted to run 'Elm init' cmd when app already running

[dotnetspec]

Linux Mint 18.3
Chrome Version 80.0.3987.149 (Official Build) (64-bit)
Elm 19.1

Everything installs and runs w/o issue.
When I click on e.g. 01-button.elm in the browser link I get:

-- NEW PROJECT? ----------------------------------------------------------------
Are you trying to start a new project? Try this command in the terminal:
    elm init
It will help you get started!

in the browser.
There is already an elm.json file at the top level, so running elm init changes nothing.
How to get the button.elm file to run?