Walmart has made some big changes to the authentication methods used by their API which necessitates code changes on anyone using their APIs.
We have made the needed changes and if you are using our Walmart Connector, you should immediately upgrade. After upgrading, all you need to do is go to your Walmart Backend objects and insert your Client ID and Client Secret, which you can get from logging into the developer portal. If you are using our Docker images, then simply re-pulling the image will suffice.