Settings > App and sales channels
Click Develop apps
Click Create an app
Enter App name (e.g. Storyclash), select App developer
Click Create app
Click Configure Admin API scopes
Set the following Admin API access scope permissions, Click Save
Click Install app, Save the app key
Check Admin API access scopes permissions
You will need to add the following data to Storyclash in order to connect the shop (see section 2 “In Storyclash”).
Shopify Help Center | Custom apps
https://help.shopify.com/en/manual/apps/app-types/custom-apps