Inventor parts (.ipt) may be exported to a format accepted by 3D printers (.stl) using several available CAD programs, including Autodesk Inventor itself. However, in case you do not have to access to the native tool for .ipt files, you will have to look for some 3rd party CAD software or some dedicated CAD converter to achieve ipt to stl conversion.
For example in Inventor you can do this by selecting File ► Export ► To CAD format and selecting STL format in the browsing menu.
Updated: June 21, 2023