To reauthorize your Shopify store's access credentials:
From your store settings page, click on the name of your Shopify store
Click on the Access credentials & integration settings panel to open it
Enter your Shopify Store URL and click the Authorize SKULabs button
If needed, login to your Shopify account
In the window that appears on Shopify, click on 'Install app'
Click the Connect 'Your Store' button
If you have any questions, please contact SKULabs support.