GitLab and MS Teams integration is not working

Hello,

Greetings!!

I am trying to integrate GitLab with MS Teams but not able complete the setup.

Steps followed:

1. Created a webhook on MS Teams channel as recommended in GitLab documentation.
2. Activated the MS Teams notification service from admin dashboard
3. Navigated to GitLab project -> Integration page and selected MS Teams
4. Checked Active, Push, Issue, Confidential Isse, Merge request, Note, Tag, Wiki boxes
5. Pasted copied webhook -> [ If I use https:// and test settings,  It is throwing me a error "test failed save 
                              anyway" when I click save anyway ..It shows MS team activated ] 
                         -> [ If I use http:// and test settings, It is says MS teams activated ]

6. Either ways i.e. with https://webhook and also with http://webhook, when I change anything and push to repository I don't see any notification in MS Team channel 

Can somebody tell me what is going wrong with the process I am following?

Thank you

Have a great day