Redmine

When I use SVN as SCM, add refs #id when commit, and I will see the corresponding changes on the corresponding issue.
Using the same method, when commit on Gitlab, the issue on Redmine cannot be tracked to the changes on Gitlab.
what should I do? thank you

Environment:
Redmine version 3.4.3.stable
Ruby version 2.3.3-p222 (2016-11-21) [i386-mingw32]
Rails version 4.2.8
Environment production
Database adapter Mysql2
SCM:
Subversion 1.9.7
Git 2.14.1
Filesystem