I bank with Wells Fargo but I’m sure it’s the same with most banks. You go under documents then statements. Print out your last statement and submit it with your offer. Sometimes they’ll want to see last 2 statements to make sure it’s really your money. It’s a non-issue.
If you try to use retirement funds you’ll have to include a statement from the provider saying what you would bet if you used those funds after taxes and fees if any.