When you log into your DigitalOcean droplet, you keep getting warning messages about updates and you need to restart your droplet to apply them.
Welcome to Ubuntu 20.04.1 LTS (GNU/Linux 5.4.0-51-generic x86_64) * Documentation: https://help.ubuntu.com * Management: https://landscape.canonical.com * Support: https://ubuntu.com/advantage System information as of Thu Mar 11 02:02:08 UTC 2021 System load: 0.0 Users logged in: 0 Usage of /: 13.1% of 24.06GB IPv4 address for eth0: 159.19.11.28 Memory usage: 72% IPv4 address for eth0: 11.37.0.5 Swap usage: 0% IPv4 address for eth1: 11.122.0.2 Processes: 120 82 updates can be installed immediately. 3 of these updates are security updates. To see these additional updates run: apt list --upgradable *** System restart required ***
To make these messages vanish you can just reboot your droplet by typing reboot (or sudo reboot)
root@ubuntu-s-1vcpu-1gb-dle1-01:~# reboot root@ubuntu-s-1vcpu-1gb-dle1-01:~# Connection to 159.19.11.28 closed by remote host.
Once your droplet reboots, you can login and see if the messages have vanished. If you still see the messages you should update all packages in your Ubuntu system.