Colleagues can't go to dinner to apologize.

It's certainly a bad thing that colleagues can't go to dinner, because it means they are not United. To this end, we should express our apologies through our own words and get the understanding of our colleagues, which will also win the goodwill of our colleagues.

In order to express our apologies well, we should find a normal and reasonable reason.

For example, I'm sorry that I can't go to my colleague's dinner because of my personal affairs, and I'm also very upset. I hope my absence will not bring you unhappiness. I wish you a happy meal.

As long as you say so, I believe my colleagues can understand.