How can I enable TPM 2.0 on my HP ProDesk 600 G1 Tower PC?

Unfortunately, your system likely doesn't support TPM 2.0 since it has a 4th gen Intel CPU. TPM was only included on desktop boards starting with the 7th or 8th gen, so your hardware can't use it.

Your model only comes with a TPM 1.2 chip, which isn't enough for Windows 11 requirements that need TPM 2.0. If you're not focused on upgrading to Windows 11, just create a bootable USB with Rufus and you can bypass the TPM requirement.