Asphox
I think I found a way. Right click on the network icon in the tray, and choose "Edit Connections...". In the "Network Connections" window select "Hotspot". Then edit the SSID on the "Wi-Fi" tab and the password on the "Wi-Fi Security" tab and hit save.
[Edit] In testing it doesn't really seem to change the name (SSID), but the password change seems to stick.
Maybe you have to do the manual editing suggested here: https://www.linuxuprising.com/2018/09/how-to-create-wi-fi-hotspot-in-ubuntu.html, or at least do the restart of NetworkManager.
[Update] So yes it does work if you do the restart of NetworkManager (sudo systemctl restart NetworkManager.service
) and the select the "Connect to Hidden Network..." and select "Hotspot" as suggested in the above link.
There's some other ideas here: https://askubuntu.com/questions/897854/how-do-i-change-wi-fi-hotspot-settings-in-ubuntu-gnome-16-04