In unity, how do I make it so that when all of my capsules (collectables) have been collected, my UI button appears? : I really need to do this this evening or a failing grade awaits. but part of the exercise im doing requires it

I have these objects that the should be able to walk into, and once they've collected all 5 of them, the UI button on the grey box in the top left corner of their screen appears. ive been spending ages trying to figure it out but I cant


I have the coding experience of an absolute beginner. this literally is my first coding experience