Please help - forgot to mention US B1/B2 Visa refusal

[Mapleleaf705]

Hello

I applied for my visa application and submitted all of the details, but I forgot to mention the US Visa refusal in the visa application, which was refused in 2015. Also, I had a refusal in 2017 for Canada, one I mentioned in the visa application form,


Now, I got a biometric request letter please help me if anything can be done.


thanks in advance.