You do not have to provide any proof, you only have to list all your travel history in the form. If you do not recall the travel dates, then you can list them with the best fo your knowledge, and include a LoE stating that you do not recall the exact dates.
Thank you for your quick response. Also, I had previous visa refusals (Canada Study permit and Australia PR) which I have declared in my application. Do I need to attach documents relating to this (like the refusal letter) in my application? It is not asked in my checklist - but I read from a few comments that I have to attach this. So I am just really confused as preferably I don't want to bombard the visa officer with a lot of documents if it is not really necessary.
Yes, that is normal, and it will stay like this until your COPR is issued. You will see changes when your medicals are passed and when your BGC changes.
Can someone clarify that in case one forgets to upload any document, does it lead to direct rejection or do they write back asking for the document? Also, if they do ask, does it lead to any major delay?