To successfully integrate your Shopify store, you must have access to an account that has permissions to add Apps to that store.
If you do not have admin or App permissions for the Shopify store that you'd like to integrate, you will need to request the permissions from the store owner.
You may also invite a team member that has the appropriate permissions and enable Manage Integrations option when you do. For more information on how to invite team members, click here.
If you are a store owner or admin and need to grant permissions to a staff account in Shopify, follow these steps:
Step 1: Go to your store Settings.
Step 2: Click Users and Permissions.
Step 3: Under Staff accounts either add a new staff account or click on an existing staff account to update.
Step 4: Ensure all "General" permissions and the ability to "Manage and Install apps and channels" is selected.
When you finish adjusting your app permissions, try adding your store once more. For more information on how to add your Shopify store, click here.