How did you do the installation?
If you install via Git, you need composer as well as myrepo, as described on our Github page: https://github.com/EGroupware/egroupware/blob/master/README.md
If you download an archive from our Github download page (https://github.com/EGroupware/egroupware/releases) make sure to use the full archives (egroupware-epl-*) and not the automatic provided ones by Github (Source code). The full ones contain all requirements and therefore need no Composer.
Anyway shared hosting servers are the worst installation platform for an application like EGroupware
Recommended is always a (maybe virtual) root-server with RPM or Apt packages for the Linux distribution you use.
Ralf