Prior to installing the Amazon WorkSpaces client you need to add the repository to your systems respository’s list. To do this follow these commands:

Ubuntu 18.04 (amd64)

wget -q -O - https://workspaces-client-linux-public-key.s3.cn-northwest-1.amazonaws.com.cn/ADB332E7.asc | sudo apt-key add -
echo "deb [arch=amd64] https://workspaces-client-updates-linux.s3.cn-northwest-1.amazonaws.com.cn/ubuntu bionic main" | sudo tee /etc/apt/sources.list.d/amazon-workspaces-clients.list
sudo apt-get update

Ubuntu 20.04 (amd64)

wget -q -O - https://workspaces-client-linux-public-key.s3.cn-northwest-1.amazonaws.com.cn/ADB332E7.asc | sudo apt-key add -
echo "deb [arch=amd64] https://workspaces-client-updates-linux.s3.cn-northwest-1.amazonaws.com.cn/ubuntu focal main" | sudo tee /etc/apt/sources.list.d/amazon-workspaces-clients.list
sudo apt-get update

Once the repository has been added to the Ubuntu OS, you can install Amazon Workspaces with the following command.

sudo apt-get install workspacesclient