Do you at least have the application ID ( I don't need it). Create a GC key account and link your paper application to you online account.
Here are the steps;
Create a new GC Key account. On the link
https://www.canada.ca/en/services/immigration-citizenship.html, click "Sign in or create an account to apply online" on right and go down a little to "continue to GC Key" and click it. Now click "Sign Up" on the right and create a new profile. Remember the answers to the security questions that you'd be setting at this time.
Once that's done, login again and click "Add (link) your application to your account " on the User's account page.
Select category as "temporary residence" and sub-category as TRV. Under "Application details" select last option. Enter UCI, no hyphens and no space. Enter Family Name as last name on passport (upper/lower case matters). Next, select passport form drop down.
Enter all other fields as filled in application form. And click "search my application". If all fields are correct it will give you the application and you can proceed with linking it. If not, it give you 4 more attempts in 24 hours and then it would ask you to try again after 24 hours.