Set ubuntu os adapter from dhcp ip to static ip

 Edit the file:

sudo nano /etc/netplan/50-cloud-init.yaml

Earlier content:

network:
  version: 2
  ethernets:
    enp0s3:
      dhcp4: true
    enp0s8:
      dhcp4: true

Replace with below content:

network:
  version: 2
  ethernets:
    enp0s3:
      dhcp4: true    # keep NAT internet as DHCP
    enp0s8:
      dhcp4: false   # disable DHCP
      addresses:
        - 192.168.195.10/24   # your desired static IP
      routes:
        - to: default
          via: 192.168.195.1
      nameservers:
        addresses: [8.8.8.8, 1.1.1.1]

Apply the change:

sudo netplan apply

Then verify:

ip a show enp0s8