how to flat pattern in inventor from imported STEP file ?

how to flat pattern in inventor from imported STEP file ?
Sample File attached. if anybody know please advice me.
Accepted answer

You can't produce a flat pattern directly from that part. That's an extruded "Z" shape. It has varying thickness across the profile. This part was not designed to be made in a flat profile.
However, if you round the outside corners with a 10mm radius so that it has a uniform cross section then a flat pattern may be obtained:
1. Set your material in the physical properties.
2. Round the outside corners with a 10mm fillet.
3. Set your sheet metal defaults to have a 4mm thickness.
4. Define A-Side and select one of the flat surfaces.
5. Go to Flat Pattern.
Note: It may not be a usable flat pattern. Many features cross the profile at odd angles. Inventor will faithfully reproduce these features wrapped into the flat pattern. You couldn't simply cut a profile using this flat pattern.
Attached is an Inventor 2022 file with the flat pattern.