Success at last. The issue was as hypothesis earlier. In order for the Intel PTT to work, you must disable legacy bios boot and boot using UEFI. However, when I enable UEFI, I was unable to boot because my boot drive used MBR and so would not boot if I disable legacy boot mode. I converted the drive using AOMEI partition assistant Pro. I believe you can use the windows tool mbr2gpt.exe, but it's more finicky about windows versions. The conversion tool a few minutes because it's a SSD. Afterwards, I was able to do the following: 1. Go into BIOS. 2. Disable legacy boot. Change to UEFI boot and select the converted GPT drive. 3. In security, enable PTT. 4. Reboot.  Windows will start up and device manager will recognize the PTT as TPS module. If you run tpm.msc as admin, it will show that it's tpm 2.0. Unfortunately, the password manager still does not store the key, but that is another issue :-(.  
The XPS 8900 does not have a discrete TPM. However, there appears to be an option for Intel PTT option in the BIOS. Intel PTT firmware should show up as TPM 2.0 when I go to TPM.msc, but instead the system tells me that there is no compatible module. When I examine the device driver, I see the following error This device cannot start. (Code 10) {Operation Failed}The requested operation was unsuccessful. I am unable to update the driver and I have install the latest BIOS (2.91). How can I get Intel PTT working?
XPS 8900 and Intel PTT