We congratulate someone on something, not "for something". However, you can "congratulate someone for doing something".

We congratulate someone on something, not "for something".

I congratulated Alice on her new baby.

I congratulated Alice for her new baby.

However, you can "congratulate someone for doing or achieving something".

We congratulated him for getting a new job.

Instead of the verb, you can use the plural noun "congratulations", and just say "congratulations on something".

Congratulations on your marriage.

Be also aware that you can "congratulate someone" or "offer/send congratulations to someone". Both are correct.

The President offered congratulations to Sarah Smith.

The President congratulated Sarah Smith.