Are you sure it doesn't have PTT? AFAIK recent-ish intel CPUs should have TPM support using the trusted computing capabilities of the CPU itself, without the need for a discrete TPM chip.
Microsoft has clarified on Twitter of all places that TPM 2.0 isn't the only requirement. It must be 8th Gen Intel or 2nd Gen Ryzen or newer regardless of whether it has a TPM.
>Firmware TPMs are firmware-based (e.g. UEFI) solutions that run in a CPU's trusted execution environment. Intel, AMD and Qualcomm have implemented firmware TPMs.