Optiplex 7450: How to Skip TPM Alert when Booting Win 10

Hi all, bought a secondhand Optiplex AIO 7450 few weeks ago and it worked fine until I updated some drivers using the Dell SupportAssist (suspect it was BIOS update). Optiplex is out of warranty.

After the update, I always get this message every time I boot Windows. I can continue booting by pressing F1.

I was advised to update TPM firmware, but failed to launch the driver (always received this error message and failed to update).

I tried various suggestions below and nothing worked:

1) Tried to enable TPM via BIOS: tried numerous times, there was no TPM options under Security (seems like TPM is totally missing)

2) Tried to unplugged desktop from AC power for 30 seconds: saw this works for dell laptop, but it did nothing to my optiplex

3) Ran Win + R then "get-tpm": I got this return, TpmPresent is shown as False. At this point, I was starting to doubt if TPM is disabled, could it be the TPM is not even there?

4) Ran tpm.msc: Returned with "Compatible TPM is not found" and there is no "Security Device" option in Device Manager. 

5) Tried https://www.dell.com/support/kbdoc/en-sg/000184894/how-to-successfully-update-the-tpm-firmware-on-your-dell-computer but this is what I got

Asking the community who may had experienced similar issues before and share their suggestions because I have exhausted my options:

1) I have no idea how it managed to skip TPM alert before the BIOS update. After trying a few things, it seems like my AIO has no TPM at all? Is there a definitive way to check whether TPM is installed without having to open the cover?

2) Is it possible to skip TPM alert when booting Windows so I don't have to press F1 every single time?

Thanks a bunch.