Quickly & be fast

Difference between Quickly and Be Fast

If you are talking about a situation such as when someone is asked to do something at speed, then there is no difference between
Please be quick
Please be fast

To ‘be fast’ can also mean to be secure, but I don’t think that is what you mean.

So, when we must use (hurry up!!)?

‘Please hurry up’ can also be used in place of the other examples.

I like such examples. Short phrases. They let me know how NES communicate in real situations. Thanks