Yes, it is possible, I currently do with satisfaction.
Just be sure that your dll.xml contains the following entry

<Launch.Addon>
<Name>IvAp</Name>
<Disabled>False</Disabled>
<Path>C:\Program Files (x86)\IVAO\IvAp v2\ivap_fsx_bootstrap.dll</Path>
<Commandline></Commandline>
</Launch.Addon>

and the [Main] section in prepar3d.cfg looks like this (otherwise you won't see any online traffic):

[Main]
User Objects=Airplane, Helicopter, Submersible, ExternalSim
SimObjectPaths.0=SimObjects\Airplanes
SimObjectPaths.1=SimObjects\Rotorcraft
SimObjectPaths.2=SimObjects\GroundVehicles
SimObjectPaths.3=SimObjects\Boats
SimObjectPaths.4=SimObjects\Animals
SimObjectPaths.5=SimObjects\Misc
SimObjectPaths.6=SimObjects\Submersible
SimObjectPaths.7=SimObjects\IVAO_MTL

Regards
Stefano

Hello,

Dll.xml the file does not exist in the directory "C: \ Users \ Yves \ AppData \ Roaming \ Lockheed Martin \ Prepar3D"

I should mention that I come today to install P3D

This file exists in the directory for FSX

I await your instructions

thank you

Yves

A dll.xml file should be created in Roaming\Lockheed Martin only after you install any add-on through a native P3D installer (if you install latest version of Fsuipc 4, you will get a dll.xml for P3D).

If dll.xml does not exist, you can just copy the one from FSX and modify it.
Delete any entry related to add-ons you don't use in P3D and keep only the xml header and the entry related to Ivap (I suppose you have already Ivap installed for FSX).

Also, just put a copy of the fsx.exe executable file into main Prepar3D folder.

Hope it will help.
Stefano

Glad to hear that.

Happy landings,
Stefano

An update of the MTL has allowed me to find the traffic
problem solved
thank you
Yves