Recommended: Connect with Walmart
New Walmart stores connect with the Connect with Walmart button in the store settings. Walmart shows the access SKULabs is requesting and you approve it there, so you don't need to set any permissions yourself. New stores can only connect this way; the Client ID and Client Secret fields are only shown for stores that were connected with an API key before.
If your store already uses an API key (Client ID and Client Secret), choose OAuth authentication under Authentication method in the store settings, then click Connect with Walmart. SKULabs then removes the old Client ID and Client Secret.
If SKULabs shows Reconnect with Walmart, the approval has expired or was removed. Click it and approve again.
Ship With Walmart needs a Connect with Walmart store
To add a Ship With Walmart carrier account, at least one of your Walmart stores must be connected with Connect with Walmart. Walmart only gives Ship With Walmart rates, including UPS rates, through that connection. If all your Walmart stores use an API key, switch one to OAuth first. Ship With Walmart carrier accounts you added before keep working.
Using an API key (Id & secret authentication)
If you connect with a Client ID and Client Secret from Walmart's API Keys page, the key needs these permissions. Some Walmart accounts create keys with no permissions, which makes order, listing or stock sync fail with 401, 402 or 403 errors.
Feeds: Get Feeds: View Only
Item Management: Content, Items, Inventory, Price, Lag Time: Full Access
Order Management: Orders, Returns: Full Access
Fulfillment: Fulfillment: Full Access
Settings, Rules & Admin: Reports: View Only (required, or listings sync can't start). Shipping and Rules can stay at No Access.
The SKULabs key permissions in Walmart's API Keys page, matching the list above.
If Walmart won't let you select some of these, save the key with as many as you can, then reopen it; the options sometimes become available afterward. If they still can't be set, contact Walmart support, or switch to Connect with Walmart above.