Crypto encode a string to match Web Crypto API

Elixir code returns proper value:

Buffer.from(await crypto.subtle.digest('SHA-256', 'mydomain.com')).toString('hex')
// => '0a79eaf6adb7b1e60d3fa548aa63105f525a00448efbb59ee965b9351a90ac31'

So you probably have some rouge characters in your NJS input.