You can set a default signature for your user account, which will be applied to all your connected email addresses.
If you want a custom signature for a specific email account, you can create one for that account. Overloop automatically adds the chosen signature to the bottom of every email you send.
How to configure your signature:
Go to Settings > Email Accounts.
Select the email account you want.
For a default signature (applied to all your emails), use the Default Signature tab.
To set a custom signature for this account, click Actions > Edit Signature, then add your text or image.
Click Save Changes.
Note: Each email account can have its own unique signature, while the default signature applies across all accounts unless overridden.