How to use issues of Gitlab from terminal?

You have a similar wrapper (in python, not ruby) with Itxaka/pyapi-gitlab

git = gitlab.Gitlab(host=host)
git.login(user=user, password=password)
git.getall(git.getprojects)

git.getissues(page=1, per_page=40)

In ruby, that would be NARKOZ/gitlab:

# set an API endpoint
Gitlab.endpoint = 'http://example.net/api/v3'
# => "http://example.net/api/v3"

# set a user private token
Gitlab.private_token = 'qEsq1pt6HJPaNciie3MG'
# => "qEsq1pt6HJPaNciie3MG"

# configure a proxy server
Gitlab.http_proxy('proxyhost', 8888)
# proxy server w/ basic auth
Gitlab.http_proxy('proxyhost', 8888, 'proxyuser', 'strongpasswordhere')

# list projects
Gitlab.projects(per_page: 5)

It can fetch issues.

GLab seems to be a great option.

GLab is an open source Gitlab Cli tool written in Go (golang) to help work seamlessly with Gitlab from the command line. Work with issues, merge requests, watch running pipelines directly from your CLI among other features.

https://github.com/profclems/glab