I'm not divorced. Can I have dinner with others?

If you are talking about holding a wedding reception with others, you will appear as the bride or groom. That's definitely impossible. How can you marry someone else if you are not divorced? The wedding reception was to announce to others. Are you married? You committed bigamy. Although it is now required to apply for a marriage certificate to be officially married. But you already have a marriage certificate, and because you can't get a marriage certificate, you have such a de facto wedding with someone else. That is to announce your bigamy to others, and others can seize this evidence and accuse you of bigamy. So think twice. Why do you have to have a wedding with someone else before divorce? If you really want to marry that man, you should divorce here as soon as possible. If your partner has been away from home for several years, you can go to court to sue for divorce. If other people are not present, divorce can still be decided in absentia. Doesn't mean you can't get a divorce if you can't find someone. You can get a divorce after a long time.