Note: they are not yet ready/finish! Please help to improve/test/etc... with a merge request.

This is not yet published in DefinitelyTyped. Therefore you've to adapt the installation a little bit. Add following dependency to your package.json:

"dependencies": {
    "@types/xlsx-populate": "git+https://github.com/JanLoebel/types-xlsx-populate.git"
},

Run npm install and that's it.

This package contains type definitions for XLSX-Populate (https://github.com/dtjohnson/xlsx-populate).

Please feel free to contribute!