Why am I encountering errors with the Subscription API on my custom app?

[Vivien1]

Hi everyone, I have a question regarding the shopify API for subscription. I am new to shopify development and have gone through the online resources/documentation regarding creating subscription apps. I am now trying to build an app to integrate with the subscription APIs for sellingPlan and subscriptionContract. I have requested and received access to the subscription API from the admin dashboard. 

The app I am working on is a node.js app built app using Shopify CLI. I have also added a product subscription app extension scaffold by running the command on CLI. 

When I try to run the createSellingPlan mutation on graphQL explorer, it returns error saying "requires access to write_products scope". But I have this access scope on my app .env file. Why am I still getting this error even though my scope contains the required access. 

What am I missing please? Because when I run the "shopify extension serve" command, and proceed to create a new selling plan for a product from the UI, nothing happens.