The odds are that your PC does already have TPM, and if it's less than 5 years old you should have TPM 2.0.
To find out if your Windows 10 PC already has it go to Start > Settings > Update and Security > Windows Security > Device Security. If you have it, you'll see a Security processor section on the screen.
The next step is to find out what version of TPM your PC has. Select Security processor details and on the screen that appears you're looking for the Specification version. It should say either "1.2" or "2.0".
Tip: If you don't see the Security processor section it may be that your device has TPM but that the TPM is turned off. To learn how to turn it on see Enable TPM 2.0 on your PC.
Important: Windows 11 requires TPM version 2.0. For more information see Windows 11 System Requirements.
Want to learn more about TPM? See Trusted Platform Module Technology Overview.