Hi @leiriard
Have you tried this? http://docs.opennebula.org/4.14/integration/references/sunstone_dev.html#adding-custom-tabs
There are an example to add the Appmarket tab to the Sunstone here https://github.com/OpenNebula/addon-appmarket/blob/master/doc/installation_and_configuration.md#enabling-the-sunstone-tabs
and there are some post related to the grunt requirejs command How to enable our own appmarket on OpenNebula 4.14 Beta 1
I hope this info will be helpful to you.
Regards