There are two possible ways to export to IFC from within https://connect.bentley.com . If you are in the Manage Versions view of the iModel, click on the ... and this will bring up the following view:

In this view, the IFC generated will be the entire iModel from that named version and no custom mapping will be available.

You can also enter the iModel to view it. Once you are able to view the iModel, click on Saved Views, then on the view you wish to export. Then click on the ... and select Export.

 

This brings up the IFC Export interface:

 

Optional Log file:

You can also optionally pick to have the log files copied to the same location as the generated IFC file by toggling "Save Logs"

IFC Format:

Select the IFC format. Currently supported formats are IFC 4.3, IFC 2X3, IFC4 RV 1.2 and IFC 2X3 CV 2.0.

User defined Mapping

Optionally, you can select a custom mapping file to be used for the IFC Export. The default mapping file can be found here: Schema mapping.

Once you click on Export, a message will appear near the top of the window:

You will receive an email once the IFC file has been generated. Go to the Project Share and download the file.