Can you put a bed topper on Chevy Avalanche?

No, you can't put a standard bed topper (like a hard or soft tonneau cover) on a Chevy Avalanche. The Avalanche's unique feature is the midgate, which allows for extending the cargo area into the cab. A standard bed topper wouldn't accommodate this midgate system. You would need a topper specifically designed for the Avalanche, which would likely be more of a custom or specialized cover that takes the midgate into account. These are less common and usually more expensive than standard truck bed toppers.