I have resigned my job with on 3 days notice my employer is saying to me that I have to get someone to work in my place or I have to stay can they do

The employer cannot make you work if you do not want to. If there is no contract that covers your employment, then they cannot sue you for not staying.  However, they could do something like refuse to pay out your vacation (if they have a policy on that) or not give you a good recommendation or list you as not eligible for rehire.