error: failed to push some refs to in gitlab

when i try push my files into my git repository it shows some thing like this

Admin-PC MINGW64 /E/GIT-PJT (master)
$ git push origin master
To ssh://192.168.5.108:2565/root/my-project.git
 ! [rejected]        master ->  master (fetch first)
error: failed to push some refs to ' ssh://git@192.168.5.108:27692/root/my-project.git' 
hint: Updates were rejected because the remote contains work that you do
hint: not have locally. This is usually caused by another repository pushing
hint: to the same ref. You may want to first integrate the remote changes
hint: (e.g., ' git pull ...' ) before pushing again.
hint: See the ' Note about fast-forwards'  in ' git push --help'  for details.

how to solve this issue........?