I installed TexLive from https://www.tug.org/texlive/quickinstall.html in Ubuntu 18.04.
which tlmgr /usr/local/texlive/2018/bin/x86_64-linux//tlmgr
tlmgr install tex-gyre
You don't have permission to change the installation in any way, specifically, the directory /usr/local/texlive/2018/tlpkg/ is not writable. Please run this program as administrator, or contact your local admin. tlmgr: An error has occurred. See above messages. Exiting.
sudo tlmgr install tex-gyre
sudo: tlmgr: command not found
sudo su first I get
Command 'tlmgr' not found, but can be installed with: apt install texlive-base
How to perform this operation?