Once you’ve connected your Ledger to a desktop computer and entered the PIN, open the Ethereum app and check these settings:
Blind Signing: allowed
Debug Data: NOT displayed.
Ledger Nano S on a desktop
Connect your Ledger by cable, enter the PIN, turn on the Ethereum app and set it to the "application is ready" mode;
in your browser, go to https://app.1inch.io/;
on https://app.1inch.io/, click on 'connect wallet', accept the Terms of Service and select the 'Ledger' option;
if you have more than one Ethereum address on your Ledger device, you can select an appropriate one by clicking on the triangle and selecting the 'Load more...' option.
Now, you are all set to interact with 1inch in the desktop browser and confirm transactions on your Ledger.
Ledger Nano S with MetaMask
The most comfortable way to use Ledger with 1inch is to connect Ledger to your MetaMask browser extension. That way, all your actions will still require Ledger confirmation, enabling you to enjoy a full range of MetaMask functionalities without jeopardizing security.
Connect your Ledger by cable, enter the PIN, turn on the Ethereum app and set it to the 'application is ready' mode;
open the MetaMask extension in your browser;
click on the circle in the upper right corner and select ‘connect hardware wallet;
select Ledger and click on ‘connect’. If you have more than one address, select the one you plan to use;
open https://app.1inch.io/ in your browser;
click on 'connect wallet', accept the Terms of Service and select the first option, ‘MetaMask’;
confirm connection to 1inch in MetaMask.
Interact with 1inch in your desktop browser and confirm all transactions in both MetaMask and Ledger.
Known Ledger issues
No connection between MetaMask and Ledger
Ledger connected through MetaMask doesn't receive transaction confirmation requests.
Possible solution:
disconnect MetaMask from https://app.1inch.io/;
unplug Ledger;
restart the browser;
connect your Ledger by cable, enter the PIN, turn on the Ethereum app and set it to the 'application is ready' mode;
open the MetaMask extension in your browser;
click on the circle in the upper right corner and select 'connect hardware wallet';
select Ledger and click on ‘connect’. If you have more than one address, select the one you want to use;
open https://app.1inch.io/ in your browser;
click on 'connect wallet', accept the Terms of Service and select the first option, 'MetaMask';
confirm connection in MetaMask.