Please visit
https://en.cnlaunch.com/download/, find the QR code that matches the model and the first five digits of your SN, and scan it to download and install the software. Then, log in with your previous account to use it normally. Please make sure not to register again, but instead log in with your existing account.
(Applicable models include: X-431 PRO3 (V+ 5.0), X-431 PRO APEX, X-431 PRO DYNO, X-431 PRO (PROS V5.0), X-431 PRO3 APEX, X-431 PROS ELITE, X-431 PROS MINI, X-431 PROS V 5.0, X-431 PROS V1.0, X-431 V+ V4.0, and X-431 Pro 5, etc.)