How to serve acme-challenge file dynamically with Jester REST API?

Is it possible to dynamically serve the acme challenge file generated and required by certbot with rest api by jester with nim lang?

I have this code

get "/.well-known/acme-challenge/@challenge":      writeFile(getCurrentDir() / @"challenge", @"challenge")      sendFile getCurrentDir() / @"challenge"

which works if used with browser but doesn’t work with certbot.