You can always ask.
If it is a large conference with other funding sources or even an endowment, they might look at this request favorably. You would be the one in a million person to have work good enough to be accepted at a prestigious conference and might deserve an exception.
If it is a small non-predatory conference, you will have some explaining to do. By submitting a paper, you agreed to play by the rules. This means paying a registration fee, showing up, and presenting your paper. A smaller IEEE conference for instance has to break at least even (after paying a fee to IEEE to guarantee the expenses of the conference). A venue needs to be rented, coffee and tea provided, publication costs met, etc. You are now telling them that you are not keeping up your part, but if they are nice and do not complain by waiving the registration fee, you will present your paper. This is just like a kid who does not have the money for the circus, but still wants to see the elephant. I am sorry if I am a bit harsh on you, but conference organization is a hard business usually done by volunteers. Not playing by the rules creates real headaches. Now, there is a good chance that this is not a real conference (because papers by people like you are usually not publishable) in which case it does not matter.