When using example from README got: TypeError: mjml2json is not a function about mjml2json HOT 1 CLOSED

interface MJMLParsingOpts {
    fonts?: { [key: string]: string; };
    keepComments?: boolean;
    beautify?: boolean;
    minify?: boolean;
    validationLevel?: 'strict' | 'soft' | 'skip';
    filePath?: string;
}

declare module "mjml2json" {
    function mjml2json(inp: string, opts?: MJMLParsingOpts): {};
    export default mjml2json;
}

const mjml2json = require('mjml2json').default;
(...)
const output = mjml2json(input);