A quick favor stops being quick when someone has to discover its missing instructions.

The word quick describes the task in your hands, not the task in theirs. What takes you ten minutes takes an hour when the helper has to work out where the file lives, which version is current, and who to ask when it does not open. So a small favour quietly becomes a research project, and the person doing it cannot say so without sounding difficult.

Send the context with the ask: the link, the login, the one thing that usually goes wrong. Say what done looks like. If assembling that takes you more than a couple of minutes, the favour was never quick.