It seems that the preferred way of making a AP out of your Wireless NIC is to use HostAPD. However, there is an easier and out-of-the-box alternative method that can be done with single command with NetworkManager:
nmcli dev wifi hotspot
I wonder whether there is any advantage of HostAPD versus NetworkManager's hotspot
I've been googling for a while about hotspot and finally asked me the same question. I believe the answer is essentially that NetworkManager is a new feature, that shall now be used by all Ubuntu users.
HostAPD is based on ifupdown, what makes more tools for the same needs.
The only answer I've found is in French (https://doc.ubuntu-fr.org/network-manager#desactiver_network-manager_pour_laisser_agir_ifup). According to that, ifupdown is a more complete solution but NetworkManager makes the job for major usual needs, if you're not operating very complex network solutions...
Perhaps someone more educated could give a better answer.
Regards, M.
