Imported 'soap' is undefined

Question

I installed a package called soap.

This is in src/index.ts:

import soap from "soap";

console.log(soap);

I'm using ts-node-dev to compile and run.

tsnd --respawn src/index.ts
>>> undefined

This is my tsconfig.json:

{
  "compilerOptions": {
    "target": "es2016",
    "module": "commonjs",
    "esModuleInterop": true,
    "forceConsistentCasingInFileNames": true,
    "strict": true,
    "skipLibCheck": true
  }
}

Why is soap undefined, even though I'm able to go to the definition in my IDE?