Logitech was the one third party accessory company that brought out keyboard cases for the first two generations of the iPad Pro right after release. They were also the only ones besides Apple to make use of the Smart Connector for their keyboards, rather than relying on Bluetooth.
Their Create cases for the original Pro were a bit heavy and bulky, but had great backlit keyboards. The Slim Combo cases that they released right after the 2017 iPad Pros were even better. In fact, the Slim Combo for the 12.9″ Pro is still my favorite keyboard case of all time. It was a near-perfect balance of protection, portability and utility.