StoreAutomator uses variant group ids for Walmart and does not send product data for parents. Therefore, if you want to change parents on Walmart, you need to change its variant group id of the children products. You can change it by using an SKU override for the parent SKU. Overriding parent’s SKU will automatically change a variants’ group id on Walmart.
Here are the steps you need to follow:
1- Select parent and click edit.
2- Enter the SKU override that will be sent to Walmart and save it.
3- Select the parent and all variants, send product data update and sync the channel from the top left.
After the process parent sku will be updated on Walmart.
You can also create multiple parents and combine them under one master parent SKU on Walmart which is helpful to combine multiple variants under one parent listing.