Check your CPU: R1:  8th generation (2018) R2: 9th (2019) R3:10th (2020) R5 11th. (2021) Based on the 2019, it's either an R1 (technically, no revision number) or an R2.  If you see no revision number on the support page, it's an R1.  
I thought this would be so easy. I have an m17 purchased in  mid 2019. I have the service tag etc. I have gone to the support page and it just says m17. I searched in google and many other places. This should be so simple. I must be missing something. I believe it is a 3 or 4. How do I find the revision number of my m17? Thanks in advance
m17, I have been searching for the revision number?