Which service to choose for joint discussion of the code?

Question

git

There is git with gitlab installed, it is necessary to be able to discuss key issues of the system being developed, with the ability to vote on controversial issues. Preferably freeware.

Answer 1

an issue is created and commented on github. you are already dancing from the comments

Answer 2

sourcetalk.net
https://www.atlassian.com/software/crucible/overview