To report any contributions you may have missed from the First 60 Days of 2019, CRA requires you to report them on your 2018 tax return. To do so you'll need to make an adjustment or ReFile the 2018 tax return.
- If you submitted your 2018 return electronically, you can choose to do a ReFile.
- You can use your online CRA My Account if you are set up, and use "Change My Return.
- Or you can print a paper copy of the T1Adjustment form and mail it to your tax centre.
If you use CRA's Auto-Fill service to import your tax slips, these contributions may be in CRA's records and downloaded to your return as a "carried forward contribution" which can be claimed on the current year tax return.
https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/change...