USB-based external TPM?
Solution 1:
What if a laptop does not have any in-built TPM that Windows 11 requires?
At this time, based on the system requirements for Windows 11, it would mean that your laptop is incompatible with Windows 11. While you might be able to install a Insider Preview build for Windows 11, by enrolling in the Insider Preview program, eventually you will be forced to downgrade to Windows 10 if your system does not meet the final requirements for Windows 11.
Is there something like USB-based TPM that I could plug into the laptop?
The fact your laptop does not have TPM functionality strongly suggests it's also running a processor that is not on the list of processors (AMD or Intel) that are compatible with Widows 11.
My goal is installing Windows 11 on a laptop that does not have any TPM.
It is currently possible to bypass the TPM 2.0 check by replacing appraiserres.dll contained within the Windows 11 Insider Preview build ISO with the one from a Windows 10 ISO. There is no guarantee that this will continue to work once Windows 11 RTM build is released, and Microsoft has already indicated systems that are incompatible with the final system requirements for Windows 11 will be forcefully downgraded to Windows 10 by performing a clean install.