I get an error CLA_NOT_SUPPORTED on my Ledger device

CLA_NOT_SUPPORTED (0x6e00) error happens when you use an old version of the app. The solution to this is to update your Ledger Nano firmware and Ledger Live, both desktop and mobile, to the latest version.

This article from Ledger support team explains about it more : https://support.ledger.com/hc/en-us/articles/5390126989725-Solve-error-0x6e00?support=true