Python bridge functionality was not added until IDL 8.5.0. You must have at least that version of IDL or higher to use the Python Bridge. For more information on which specific versions of Python that IDL supports, see this link: https://www.l3harrisgeospatial.com/docs/python.html

Furthermore, the bridge fully supports 32-bit. However you must make sure to run both 32-bit IDL and 32-bit Python together. The only caveat here is that we dropped support for the 32-bit IDL Workbench in version IDL 8.8. If you need the bridge in 32-bit in IDL 8.8+ versions, it must be done via Command Line IDL.