How to let Mirage passthrough node modules access?

I am using SimpleMDE which seems send a request to /node_modules/typo-js/dictionaries/en_US/en_US.dic internally.

How to pass this GET request using Mirage?

I am using the following setting with no effect.

  this.passthrough('node_modules/**');
  this.passthrough('node_modules/typo-js/dictionaries/en_US/en_US.dic');