Right now, Odoo.sh only works with GitHub. Other version-control systems, such as GitLab and bitbucket, are not supported right now. If you want to use a system other than GitHub, you can use the intermediate GitHub repository that is linked to your actual repository via the submodule. In the future, Odoo will add support for GitLab and bitbucket, but this is not the priority at the moment, according to the Odoo officials. The method suggested here is just a workaround if you want to use GitLab or bitbucket.