How to emulate a curl request using node-fetch module
Authorization header is wrong.
-u "client_id:secret"says that curl is using a Basic Authentication.
You should add authorization header
Authorization: Basic <base64 encoded "client_id:secret">
Solution using yours as base, since I struggled a few minutes to have it working.
// get the client_id and secret from https://developer.paypal.com/developer/applications/const clientIdAndSecret = <client_id:secret>const base64 = Buffer.from(clientIdAndSecret).toString('base64')fetch('https://api.sandbox.paypal.com/v1/oauth2/token', { method: 'POST', headers: { 'Content-Type': 'application/x-www-form-urlencoded', 'Accept-Language': 'en_US', 'Accept': 'application/json', 'Authorization': `Basic ${base64}`, }, body: 'grant_type=client_credentials'})