That would be Det finns inget att oroa sig för in Swedish. There's a difference in meaning here: in the "There is"/"Det finns" versions, reasons to worry do not exist. But in the "It is/Det är" versions, it's a specific thing or situation that does not give cause for concern.
It's not a literal translation but "it's not worth worrying about " sounds more natural
I wrote: "Det är ingenting att oroa sig för." which was marked wrong. Should this be allowed, or do we have to use "inget" here to match back to "Det"?
Since you're writing in this forum, I suppose you got it as a dictation exercise? In that case, you need to write what the voice says. If you get this sentence as a translation exercise from English into Swedish, ingenting is an accepted answer, but then you'd be commenting in the reverse sentence forum instead of here.