The body is a brep body rather than a sheet metal body.
Fusion 360 sheet metal unfolding failed.
Unable to unfold a part in fusion 360.
When selecting the unfold command the model body becomes transparent.
If sheet metal does not appear there enable parametric modeling mode by capturing design history.
Now the body can be selected in the unfold command.
Right click on the top component of the design in the browser sheet metal tab is missing in fusion 360 fusion 360 autodesk knowledge network.
Only sheet metal bodies can be unfolded.
Now you get why fusion 360 s sheet metal is different.
Fusion 360 has released the sheet metal modeling environment.
Fusion 360 is the only tool to integrate design to manufacture.
To unfold the body convert the body to a sheet metal part.