When ending a sentence with a question mark (?) you are asking the person or people you are talking to a question for which you would like an answer. Here you are asking permission to do a particular action.
Here are some examples:
“Can I answer your question?”
“Can I attend the event?”
“Can I move to another spot?”
“Can I call you tomorrow?”
“Can I complete this later?”
“Can I explain myself?”
“Can I help you with your homework?”
“Can I include you in our plans?”
“Can I introduce you to my co-workers?”
“Can I inform you of some bad news?“