In Spanish, “Congratulations” is commonly translated as “¡Felicidades!”.
You can also say “¡Enhorabuena!”, especially in Spain, which is often used for significant achievements like promotions, awards, or big milestones.
So, both “¡Felicidades!” and “¡Enhorabuena!” are appropriate, but “¡Felicidades!” is the most widely used.