We added this question to tackle it in a deeper manner than you might think!
You can and should be able to provide your dog with a basic command like Sit, Down, or Stay when you'd like. But no matter the command you're hoping they listen to, you first need to make sure you are listening to them, while also asking yourself why you're asking them to do it in the first place.
Is your dog feeling stressed, nervous, overly excited, or perhaps worried and concerned? All of those are valid feelings and are there for a reason. Keeping that in mind if we are asking a dog to sit in circumstances where your dog is feeling that way, are we doing so in the hopes of getting them to just put that feeling aside? Or are we doing it to help them regulate their own emotions and start to feel a different way?
Taking into consideration how our dogs feel when we're asking them to do something is the key to knowing when and whether we should ask for a command, no different than doing our best to understand other people, before expecting them to do things for us!