Unable to use AppBuilder studio

Hi,

Quite new to Axelor, I have installed 5.3.9 from WAR. I can see the studio module but I cannot install the AppBuilder application. Apologies if this is very n00b.

How do I install/activate the appbuilder?

Many thanks in advance!

Installation path, on Open Suite v6.0.3: Application config > Apps management > BPM