You don't need to steal a license key. There are legitimate loopholes to unlock Pro features temporarily.
Click on the "Register" or "Upgrade to Pro" button, usually found in the top-right corner or within the settings menu. Sejda Pdf License Key
Download the official installer for Windows, Mac, or Linux from Sejda's website. You don't need to steal a license key
Note that "Web-only" plans do not include a license key for the Desktop version. Sejda Pdf License Key