If you are using Ledger in conjunction with your Metamask, you will be required to enter the settings of your Ledger and "Enable Blind Signing".

Blind Signing is required when interacting with smart contracts using Ethereum dApps through Metamask.

Enabling blind signing

1. Connect and unlock your Ledger device.
2. Open the Ethereum (ETH) application.
3. Press the right button to navigate to Settings. Then press both buttons to validate.
4. Your Ledger device displays Blind Signing.
5. Press both buttons to enable transaction blind signing.
6. The device displays Enabled. You're done.

Information sourced from Ledger's Official site - https://support.ledger.com/hc/en-us/articles/4405481324433-Enable-blind-signing-in-the-Ethereum-ETH-app?docs=true