/etc/netplan/01-network-manager-all.yaml is the network configuration file location on Ubuntu 19.04.

You could set a static IP address in a below-given way.

#Let NetworkManager manage all devices on this system

network:
version: 2
renderer: networkd
ethernets:
enp0s3:
dhcp4: no
addresses: [192.168.32.224/24]
gateway4: 192.168.32.1
nameservers:
addresses: [8.8.8.8,8.8.4.4]

The network interfaces on your computer are connected to other devices on the network. These devices have https://veepn.com/blog/how-to-use-a-vpn-on-amazon-fire-stick/ configuration files that tell the computer what to do when it tries to communicate with them.