EOS R5 How can I check my camera validity?

[fima]

Hello, I've purchased my Canon EOS R5 from a third-party seller through Walmart in USA.
My camera's serial number starts with 25222... 
I tried to register the product through https://myprofile.americas.canon.com/us/addProducts but it says:

The serial number you have entered is invalid for one or more of the following reasons:
1) The serial number does not match the product you have selected (FCC ID which starts with “AZD” is often mistaken for serial number.)
2) The serial number entered indicates this product was not intended for sale in the United States and is ineligible for registration and support in the U.S.
Please verify your product model and serial number to ensure they were entered correctly.

How can I make sure that the camera is from Canon?

[shadowsports]

Just looked in "my canon" account.  I have a list of all serial numbers in my account, so I compared them.

I noted that some of serial numbers I registered with were appended.  My R5 C shows 10 digits (last 10).

My 6D2 shows 20 digits.  (I know I only used 10).  My T6s shows 12 digits, but it was sold.  I do not believe you can get support or repair without registration.   Not 100% sure about this.   

[jcschultz01]

I called Canon about a used R5 (MK 1) and the 3rd and 4th numbers of the serial number are 20 if the camera is a US model.  For example 2520xxxxxxxx. Hope this helps others too.  Canon has been nice on the phone but just providing the information online is a lot faster than being on hold.