Is it possible to not gain weight on a calories surplus?

Technically no, a caloric surplus/deficit is the end-all-be-all for weight gain/loss. However, you can easily get around this.

Eating in a caloric surplus implies that you eat more calories than your body burns in a day. The easiest way around this is to increase your activity level. That way, even if you eat enough food to be in a caloric surplus, lifting weights or cardiovascular exercises can burn enough calories to put you in a deficit.

Activity level should always be included when calculating calories needed per day (depending on your goals) but many people neglect to include it.

Here’s a great tool I use that helps you calculate how many calories your body burns daily using your height, current weight and activity level: Calories Calculator