It’s pretty easy to create a hotspot in Ubuntu and Ubuntu-based distributions. Following this article will help you easily create a hotspot:
https://ubuntuhandbook.org/index.php/2014/09/3-ways-create-wifi-hotspot-ubuntu/
You are lucky if you get it done on the first run. But if you see the “AP Mode Not Supported” message, you need to dig in like I did — it’s a driver issue. All you need to do is hunt for the correct drivers. Follow the article linked below:
https://ubuntuhandbook.org/index.php/2014/09/wifi-hotspot-access-point-not-supported/
Follow steps 1 to 7.
If you don’t find your drivers in Additional Drivers, make sure you have completed step 7, then restart the PC.
Remove the existing driver:
sudo modprobe -r wl
Load the newly installed one:
sudo modprobe brcmsmac
Repeat step 3. Check the current driver running on your Wi-Fi adapter by running the command below:
ethtool -i wlan0 | grep driver
The result should NOT look like this (anything other than this is welcome):
driver: wl0
You are now ready to create a hotspot with the steps mentioned in Ubuntu Handbook.