You should be able to manually add those attributes if they aren't present. It's worth noting that urn:ietf:params:scim:schemas:extension:enterprise namespace is a protected namespace for the User Enterprise schema extension defined in the SCIM RFC, and Snowflake's SCIM implementation is violating the SCIM standard if they are still using that namespace. They should be using something such as urn:ietf:params:scim:schemas:extension**:snowflake:**2.0:User:defaultRole instead. Mapping to these attributes may not work consistently as defaultRole and defaultWarehouse are not a part of the User Enterprise schema extension.
I'll let our team that manages the tutorials know that the screenshots should be updated to reflect the current state of the integration as well.