Unable to integrate DVCS with hosted gitlab

HI!
I am going through the below link and everything configured in DVCS-Jira and Gitlab. But when i click on add button from DVCS modal window from jira getting 404 error. Though i have given all the permission to the application in gitlab.

Gitlab: Its running inside docker with external postgres database and its working absolutely fine.

Gitlab production logs shows the below logs when try to add/integrate DVCS with gitlab

Started GET “/admin/applications” for 127.0.0.1 at 2019-02-26 16:38:33 +0530
Processing by Admin::ApplicationsController#index as HTML
Completed 200 OK in 106ms (Views: 66.7ms | ActiveRecord: 9.7ms)
Started GET “/uploads/-/system/appearance/header_logo/1/T1.png” for 127.0.0.1 at 2019-02-26 16:38:34 +0530
Started GET “/uploads/-/system/user/avatar/1/avatar.png?width=23” for 127.0.0.1 at 2019-02-26 16:38:34 +0530
Processing by UploadsController#show as HTML
Parameters: {“model”=>“appearance”, “mounted_as”=>“header_logo”, “id”=>“1”, “filename”=>“T1.png”}
Processing by UploadsController#show as HTML
Parameters: {“width”=>“23”, “model”=>“user”, “mounted_as”=>“avatar”, “id”=>“1”, “filename”=>“avatar.png”}
Sent file /home/git/gitlab/public/uploads/-/system/appearance/header_logo/1/T1.png (0.2ms)
Completed 200 OK in 32ms (ActiveRecord: 4.3ms)
Sent file /home/git/gitlab/public/uploads/-/system/user/avatar/1/avatar.png (0.2ms)
Completed 200 OK in 32ms (ActiveRecord: 7.5ms)
Started GET “/admin/applications/3” for 127.0.0.1 at 2019-02-26 16:38:37 +0530
Processing by Admin::ApplicationsController#show as HTML
Parameters: {“id”=>“3”}
Completed 200 OK in 95ms (Views: 63.1ms | ActiveRecord: 6.3ms)
Started GET “/uploads/-/system/appearance/header_logo/1/T1.png” for 127.0.0.1 at 2019-02-26 16:38:38 +0530
Started GET “/uploads/-/system/user/avatar/1/avatar.png?width=23” for 127.0.0.1 at 2019-02-26 16:38:38 +0530
Processing by UploadsController#show as HTML
Parameters: {“width”=>“23”, “model”=>“user”, “mounted_as”=>“avatar”, “id”=>“1”, “filename”=>“avatar.png”}
Processing by UploadsController#show as HTML
Parameters: {“model”=>“appearance”, “mounted_as”=>“header_logo”, “id”=>“1”, “filename”=>“T1.png”}
Sent file /home/git/gitlab/public/uploads/-/system/user/avatar/1/avatar.png (0.2ms)
Completed 200 OK in 31ms (ActiveRecord: 3.9ms)
Sent file /home/git/gitlab/public/uploads/-/system/appearance/header_logo/1/T1.png (0.2ms)
Completed 200 OK in 39ms (ActiveRecord: 4.5ms)
Started GET “/login/oauth/authorize?scope=repo&client_id=f1764d9777dfa09d15aee10a4cf4872dc853bbf&redirect_uri=https%3A%2F%2Fcompany.atlassian.net%2Fsecure%2Fadmin%2FAddOrganizationProgressAction%21default.jspa%3Furl%3Dhttp%253A%252F%252Fgitlab.domain.com%26atl_token%a5a-926c-d6cdd76d0621_5cd41cf59fbeede950a17908920b3e916206a17e_lin%26organization%3Duser%40domain.com%26autoLinking%3Dtrue%26autoSmartCommits%3Dtrue%26t%3D3” for 127.0.0.1 at 2019-02-26 16:38:53 +0530

please help me with this