The only native method provided to reactivate Windows after a hardware change is to use the Troubleshoot button in the Activation settings, and select 'I changed my hardware', if you did not link your device to your Microsoft account, that process will not work.
Open Command Prompt as administrator and run this command to force your system to try to contact the activation servers and activate Windows.
slmgr /ato
If that process is not successful, then because your old hardware was never linked to your account, you will need to contact Microsoft Support directly to ask them to reactivate your Windows licence for you.