about firmware download

Hello, I have purchased a BaseUNIT (HW ver.5.1).
I purchased it several years ago.
What kind of support contract do I have to sign to download the new firmware?

I have the same hardware version, and I initially thought it was some sort of bug since I was able to easily download their firmware before. After communicating with them via email, they provided me with this link to download the latest firmware update: https://infrasensing.com/support/firmware.asp. I hope this helps!

Thanks Clara-san.
I will try to email support.
Thank you very much for your comments.