If you have a board you'd like people to be able to download files from without having to be signed in, you can enable public downloads.
Go to the Board Options menu ("..." at the top of your board) and select "Enable public downloads". This is super useful if you have a photo or logo library that you need to give everyone easy access to - all they need is the board URL.
Just remember that sharing the board URL with someone won't make it pop up on their boards list. If you'd like the board to appear on someone's list, you need to either
💡 If you're sharing a board that your team will need frequent access to (like a logo library), you could ask them to bookmark the URL so they always have it to hand 😊