Whether your habit of skipping dinner will lead to weight gain or weight loss depends on the reason why and how you are skipping it.
If you are not careful about your eating habits and are not munching on unhealthy stuff in the evening then skipping dinner might help you in some way. Else weight gain is inevitable. If you choose to skip dinner, plan your meal carefully and distribute your calorie throughout the day carefully. Most people following intermittent fasting skip one meal a day (mostly dinner) to make sure they consume the entire calories in the eating window. But it becomes quite difficult for them to stay in the fasted state for longer, so they eat healthy snacks in the evening to keep themselves full. Intermittent fasting is not a diet. It is an eating pattern, which has proven to be quite effective for all those trying to shed kilos. If you plan to skip your dinner it is better to follow intermittent fasting as it is more effective.