You need to register an account on https://business.forudesigns.com/ and approved a business man with other stores (like Shopify store ) or wholesale /dropship orders .
1 Manage private apps
2 Create a new private app
3 Fill Private app name. e.g. Forudesigns、Emergency developer email, e.g. your email
4 Grant permissions
|Orders, transactions and fulfillments||Read and write|
|Product, variants, and collections||Read and write|
6 Grab your store url，API key，Password，Shared Secret