The supported way to install Windows 11 is to encrypt your VM, then you can add the TPM. There's also a preview way to add TPM without encrypting the VM, you can do this by setting the VM's hardware compatibility level to "Workstation 16.2.x" and then editing the .vmx file manually (in a text editor) and adding the line managedvm.autoAddVTPM = "software" to it; note that currently such VMs can't be moved to a different system.
