error - ReferenceError: require is not defined in ES module scope, you can use import instead

This file is being treated as an ES module because it has a '.js' file extension and '/node_modules/convertkit-react/package.json' contains "type": "module". To treat it as a CommonJS script, rename it to use the '.cjs' file extension.

Start by inspecting package.json and the JavaScript file that triggers the reported require error to confirm how the package is treated as an ES module. Reproduce the error, then verify that the chosen module-format change removes it without breaking the package's existing behavior.

Written by the indexing model from the issue text.