Can’t afford fence

We have a neighbour who’s recently been broken into and it looks like they might want to get a fence between an unfenced section of our property.

We think it was never fenced as it’s a very awkward part of land.

We understand if they issue a fencing notice we would have to contribute, but what if we can’t financially?

I think it is going to be pretty expensive due to its awkwardness, and we don’t have the money to pay it. Would we be able to pay it off? Or what happens in this situation?