After installing LibreOffice 5.4.6-ubuntu 17,10

I cannot launch LibreOffice only by instruction
/opt/libreoffice6.0/program/soffice

What is “installing LibreOffice 5.4.6-ubuntu 17,10”? Is it using the OS package manager to install an official distro package? or from a PPA? or installing a snap package? or maybe a DEB from TDF site? or … ?

@arie - Please edit into your question all relevant information (OS, LibO version, etc.). Thanks.