Howdy @gp-xyz and welcome! 
This looks similar to Problem with FaunaDB function- import failure. Have you tried the solution in that post?
FYI, answered my own question: I needed to have a package.json file listing faunadb as a dependency, and then I needed to specify a build command that runs npm install. Once I did that, I got past the dependency issue (having another issue with the query, but that’s entirely on me).