Roundcube Problem Update

[mymmo73]

Hi, I'm new to the forum I state that I'm not proficient with linux, I only know some basic command line. But I was able to install debian 10 with ispconfig on a web server by following tutorials, then also roundcube, and everything worked fine. Now I wanted to update my roundcube because of the new Elastic skin, to make the webmail optimized for mobile devices, also here I have followed many tutorials that are on the net but I can't do it in any way, I accept any suggestion thanks.