Did you receive Universal child care benefit (UCCB) or the Canada Child Benefit (CCB)? The Canada Child Benefit (CCB) replaced the Universal child care benefit (UCCB) and the Canada child tax benefit (CCTB). The UCCB was discontinued as of July 1, 2016, so except in rare cases, most people would not have gotten a RC62 slip after 2016.
If you did get an amount for the UCCB, then it is taxable and you will get a RC62 to enter into your return. If you got the new CCB, it is *not* taxable and doesn't need to be entered on your tax return. However, you (and your spouse/partner if applicable) must file your tax return every year to continue to get your CCB payments. Filing your return late may lead to late payments.
You can get more information on the Canada Child Benefit from the Canada Revenue Agency (CRA), including how to apply for the CCB: Canada child benefit