OpenIGTLinkIF module is not loaded

Hi,

I built Slicer 4.13.0 in Ubuntu 20.04.3 LTS and then I installed the following extensions using the Extensions Manager:
Untitled2

After the installation, I restarted Slicer but I noticed that only some IGT modules are present, as you can see from the following screenshot:

Searching for OpenIGTLinkIF module I saw this message:
Untitled

Do you know what I should do to use OpenIGTLinkIF?

Thank you

If you have built Slicer, then you will need to build all of the extensions that you need as well. The extensions downloaded from the Extension Manager won’t be compatible.

Some more info here:

Thank you! I did like you said, but now I have an other strange issue Multiple sessions of Slicer are launched in a loop - Support - 3D Slicer Community

but,if there are two modules are needed to be applied in customized Slicer app, how to build the two extensions?