[Trisquel-users] Re : How can I watch youtube videos?

[lcerf]

SMTube is not in Trisquel's repository.  It is in a PPA (read  
https://trisquel.info/en/wiki/how-software-installation-trisquel-different-windows  
for the different ways to install a program):
$ sudo add-apt-repository ppa:rvm/smplayer
$ sudo apt update
$ sudo apt install smtube