Thank you for the information bro.You need to respond and confirm you have previous refusals. You should provide the details of those refusals including information such as the country, date of refusal, and why you were refused. You need to say that you made an error in not including this information in the application. You can't blame a friend - it is your responsibility for ensuring all of the information in the application is accurate and complete. You then have to hope that IRCC does not make the decision to give you a 5 year misrepresentation ban. If you are uncomfortable or worried about responding on your own, now is the time to hire an immigration lawyer in Canada to help you.
But I have lost the refusal letters I don't know the exact date of refusal. but I remember the refusal reasons was.so Can I make it with out the date of refusal.?