How to configure .yaml wifi ap mode for minecraft server?

I setup 21.04 arm64 server and installed minecraft bedrock edition 1.17.11.1 server. It's on a pi4/8.

I can access wifi with the 50-cloud-init.yaml. I installed all updates and have the server autostart at boot and its running.

I've been thinkering with the wifi trying to get it to broadcast an id to log into it (about 30 videos and hundreds of pages) no luck. I've rewritten .yaml up the wazoo for 2 days now.

I don't want multiple devices routers wifi extenders, just a wifi connection into the pi with access to the server from tablets. A portable minecraft server my kid can operate.

Any help on setting up the .yaml?

50-cloud-init.yaml that works:

[
network:
    ethernets:
        eth0:
                dhcp4: true
                Match:
                       driver: bla bla bla.
                Optional: true
                Set-name: eth0
    version: 2
    Wifis:
        wlan0
            optional: true
            access-points:
                Mywifi:
                    Password: morethan8digits
            dhcp4: true.
]

This works to connect to my local network for internet access to run updates.

I need to change the wifis: wlan0 to an access point so as stated above it becomes a stand alone minecraft server that a child can access from a tablet, or ap mode.

The configuration required to offer your wifi as an AP is:

wifis:
  wlan0:
    mode: ap

Then include your access-point information as before (name and password).

You need to have the network-manager package installed in order to use AP mode, as documented at https://netplan.io/reference/#properties-for-device-type-wifis%3A. It is not installed by default on Ubuntu Server images.

You will also almost certainly need to configure a static IP for this interface, as there will be no DHCP server running on this network.