Update README.md

openairinterface5g/openairinterface-install-scripts/README.md

@@ -62,7 +62,7 @@ In a Linux Terminal, follow the steps below:
 > 
 > curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
 > 
-> sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu \\$(. /etc/os-release; echo "\\$UBUNTU_CODENAME") stable"
+> sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
 > 
 > sudo chmod a+r /etc/apt/keyrings/docker.gpg
 >