mammut npm installnpm start import mammut from "mammut"; const instance = new mammut.Instance("mstdn.jp"); instance .client({ name: "Test", scopes: ["read", "write"], redirect: "http://localhost:8080", }) .then(client => { const authenticationURL = client.authURL(); window.open(authenticationURL); // Let the user authenticate your app in the instance's web page. // Then you can get callback access to that "redirect" url, // with authentication code as `?code=xxxxxxx` });