Adapted from the official Shopify help article: https://help.shopify.com/en/manual/apps/custom-apps

Enable custom app development from the Shopify admin

Before you can create a custom app for your store, you need to enable custom app development. You need to be the store owner or a staff member with the Enable app development permission to enable custom app development.

Note: If custom app development is already enabled, you may skip to step 1 in the next section.

Steps:

1. From your Shopify admin, click Settings in the lower left corner
   
   
   

2. Select  Apps and sales channels in the left menu
   
   
   

3. Click Develop apps for your store.
   
   
   

4. Click Allow custom app development.
   

5. Read the warning and information provided, and then click Allow custom app development.
   

Skip to step 3 in the next section.

Create and install a custom app

The store owner, and collaborators and staff members with the relevant permissions, can create and install custom apps.

Create the app

1. From your Shopify admin, click Settings > Apps and sales channels.

2. Click Develop apps.

3. Click Create an app.
   
   
   

4. In the modal window, enter an App name eg “DX1” 

5. Click Create app.
   

Select Permissions

After creating the custom app, you need to assign permission (API scopes) to view orders.

1. Click API Credentials
   
   
   

2. Select Configure Admin API scopes
   
   
   

3. In the list of permissions, scroll down and select the checkbox next to read_orders in the Orders section

4. Click Save.
   
   
   

5. Click Install app
   
   
   

6. A confirmation window will appear. Select Install
   
   
   

7. Select Reveal Token Once
   
   

8. Copy the entire token. Send this value, along with the URL for your Shopify store, to DX1 Support at dx1support@dx1app.com to activate Order Import.