If your contributions are on a T slip, then they will be auto-filled by the CRA. If they are not, then you should get a contribution receipt which you would have to enter in manually.
Contribution made in the first 60 days of 2023 are for tax year 2022, so you would need to enter them on your 2022 return.
You can use Refile to add the RRSP contribution to your 2022 return. This FAQ tells you how: https://turbotax.community.intuit.ca/turbotax-support/en-ca/help-article/accounting-bookkeeping/file...
