In your assembly do a File > Save As > Select the appropriate file type > Check the Options tab for that file type and change settings as needed.
Good morning Rodrigo,
When you export your sheet metal design in the formats listed you need to save one file as bent and a copy of that same file in the flat pattern.
Saving it other than a SolidWorks file takes away the sheet metal features, therefore if you save the file as an igs or step, the file is saved as a solid object not a working file.
Again; it takes two files per part, one as a bent pc and the other as a flat pattern.
Welcome to the forum.
What John said is exactly right. I would add that you have to remember that when you
export these files they become what are called dumb solids. That means they do not
retain the features or characteristics of the original. The only way you would come close
is if you were exporting as a Pro-E file in solidworks and then called the file up in Pro-E.
In that case it would come in with unconstrained features.