But in your sentence, ketchup is personified, which may be a nickname of a person or an anime character.

If it is simply translated according to ketchup, then it is'

Thanks for the ketchup.

It's a lovely statement, but it's not usually said that.

Generally speaking, I would say.

ケチャップをぃて, ぁりがとぅござぃま.

ケチャップをくれて、ありがとう。

If ketchup is personified,

And then translate it into,

Thank you for supporting ketchup.

There is no context and I don't know which one is correct.