“format cjs”; What does this sentence mean

  node.js, question

This string is in the header of all files that npm publish goes out.
But I am using the following

Import file defined by export default failed

Remove format cjs to import

It should be.format commonjsAbbreviation for.
Npm module should pressCommonjsOrganization module, so press ES6 module use will be undefined

I didn’t understand what the subject said

But I am using the following
Import file defined by export default failed

What’s the meaning of