Use suspense. Keep them guessing about what will happen next. Drop little hints here and there.
One way is to vary your tone and pacing. When there's an exciting part, speed up a bit and use a more energetic voice. For the slower, more reflective parts, slow down. Also, include some humor or unexpected twists in the story. People love to be surprised. For instance, if it's a story about a normal day at work, suddenly introduce a strange customer or an unexpected task. This will keep their attention. Another important thing is to make it relatable. If people can see themselves in the story, they are more likely to stay engaged.
Engage your audience by asking questions in the middle of the story. For example, 'What would you have done in my situation?' This makes them feel involved. Also, use vivid descriptions so they can picture the events clearly. If it's a story about a place, describe the colors, the smells, the sounds. And don't forget to keep the story moving forward. Avoid getting stuck on one small detail for too long. If there are long, dull parts, try to condense them or skip them altogether if possible.