My sons BeaverScout group just gave us a link to print receipts for the registration fee and said it can be used as a Child Tax Credit (after I've filed). Is this true?

[TurboTaxLise]

The Federal Fitness Credit and many of the equivalent provincial credits were discontinued starting in 2017. 

But If you live in MB, QC or the Yukon, you'll enter your activity amounts in the Dependant credit section. 

Once the Profile Section of your return has been completed; select Deductions > Claims for Dependants.

For more information - TaxTips - Line 365 Federal Children's Fitness Amount Tax Credit - https://bit.ly/2Xkyal7

If you are part of these provinces, then I would suggest you wait for your NOA, then process a Refile if needed.