Can I use Touch ID on 2020 I Mac 27 inch

No.

Touch ID requires a Mac with Apple silicon running macOS 11.4 or later.

Your iMac has an Intel processor and not Apple silicon, so doe snot meet the requirements for using Touch ID.

+1, no you cannot.

I have to admit it would be cool to have that feature ( I also have a 2020 27") but alas it simply isn't going to happen.