You must usually have been given a permit before travelling to Denmark if you are outside of Denmark when you submit your application.
If you want to fly to Denmark before SIRI has finished processing your application provided:
You are a resident of a country that allows you to visit Denmark without obtaining a visa,
You are a citizen of a country that requires a visa but has already been granted a visa for Denmark or another Schengen country, or are a citizen of a country that requires a visa but has already been granted a visa for Denmark or another Schengen country
You have a residency permit in another Schengen nation