The only legitimate way to obtain a valid license key is to buy a subscription:
Avoid "license generators" or "cracked" versions found on third-party sites like GitHub or forums. These are often bundled with malware and violate PortSwigger's terms of service, which can lead to legal action or compromised security testing environments. DAST Software Pricing Comparison: Burp Suite, Nessus & More How To Get Burp Suite Professional License Key
Visit the Burp Suite Professional purchase page on PortSwigger's site. The only legitimate way to obtain a valid
Each invited user will receive an email with instructions on how to set up their own account and access the shared subscription license. How To Get Burp Suite Professional License Key