We are so sorry for this inconvenience.
Shopify upgraded API, and Ryviu might get trouble when accessing your store so please follow exactly the steps below to update Ryviu app to fix this issue and reconnect your store with Ryviu:
STEP 1: Log in to your Shopify admin > open Apps, then click on Ryviu - Product Reviews to log in to your Ryviu account:
STEP 2: Update Ryviu app
In the homepage of your Ryviu dashboard, please click on Reconnect in the notification appeared.
Click on Install now button to reconnect your store.
You are done :)
If you have any queries or need any assistance, please don't hesitate to contact our support team.
Thank in advance,