cant send BTC with electrum smart wallet connected to ledger device.
Unfortunately, that is not very descriptive of what your issue actually is. Can you be more specific?
Is the Ledger device communicating with Electrum OK? Do you see a "green Ledger icon":
or a "red Ledger icon"?
Where/when exactly does it fail? When you're trying to create the transaction? When you're trying to "sign" the transaction? or when you're trying to broadcast the transaction?
What version of Electrum are you using?
What Ledger device are you using?
Are you getting any error messages?