I am from Nigeria and want to get my undergraduate degree in Canada,?
It can be explained to the universities or colleges how you explained it here. All colleges and universities are aware of the academic disruptions caused to students due to covid. I would recommend that you submit a letter from the principal or a teacher explaining the situation and send it directly to the colleges/universities you plan to apply to. This will make the situation more understandable, reliable, and convincing. They will know that you are at least not lying. Another suggestion would be you talk directly to the institution and explain things. Hopefully, they will suggest everything you need and will provide an accurate guideline.