Here are the steps to upgrade Ubuntu 20.04 to the next long-term support release, which is Ubuntu 22.04 LTS:
1. Update your current system: Open a terminal and run the following commands:
```
sudo apt update
sudo apt upgrade
sudo apt dist-upgrade
```
2. Install the update manager: If you don't have the update manager already installed, run the following command in the terminal:
```
sudo apt install update-manager-core
```
3. Update the release prompt: Open the `/etc/update-manager/release-upgrades` file in a text editor (such as Nano or Vim) and make sure that the `Prompt` line is set to `lts`. If it is not, change it to `Prompt=lts`.
4. Run the upgrade tool: Run the following command to start the upgrade process:
```
sudo do-release-upgrade
```
5. Follow the prompts: The upgrade tool will guide you through the upgrade process. Make sure to carefully read and follow the prompts.
6. Reboot your system: After the upgrade is complete, you will need to reboot your system to apply the changes.
Note that upgrading your operating system can be a complex process and may take some time. It's important to back up your important data before proceeding with the upgrade.
