You can enter any version of a valid Bitcoin extended public/private key and convert it to another version of the same extended key. (For example, exporting an xpub/ypub/zpub from Ledger Live to use in some other wallet or tool.)
For more info see SLIP-0132.
The online version of this tool should only ever be used for working with extended public keys (xpub, etc) or for testing/education purposes...
You should normally never need to convert or handle xprv keys except in VERY SPECIFIC recovery situations... Working with extended private keys (xprv/yprv/zprv, etc) should only ever be done in an offline (all networking disconnected), amnesic environment like TAILS Linux... Click here to download a zip file containing this tool to run offline