Blank page using HTTPS

Hi I have an issue with Gitlab, I already configured the SSL and certificate, but I’m unable to use gitlab with https, I have to remove the s at the end of https in order to watch that page, I really don’t know how to do the troubleshooting, here is my info:

System information
System: Ubuntu 16.04
Current User: git
Using RVM: no
Ruby Version: 2.3.3p222
Gem Version: 2.6.6
Bundler Version:1.13.7
Rake Version: 10.5.0
Sidekiq Version:4.2.7

GitLab information
Version: 8.16.4
Revision: f32ee82
Directory: /opt/gitlab/embedded/service/gitlab-rails
DB Adapter: postgresql
SSH Clone URL: git@
Using LDAP: no
Using Omniauth: no

GitLab Shell
Version: 4.1.1
Repository storage paths:

default: /var/opt/gitlab/git-data/repositories
Hooks: /opt/gitlab/embedded/service/gitlab-shell/hooks/
Git: /opt/gitlab/embedded/bin/git

external_url '
gitlab_rails[‘backup_path’] = “/tmp/git_backup/”
nginx[‘enable’] = true
nginx[‘redirect_http_to_https’] = true
nginx[‘ssl_certificate’] = “/etc/gitlab/ssl/server.crt”
nginx[‘ssl_certificate_key’] = “/etc/gitlab/ssl/newserver.key”
nginx[‘listen_port’] = 81
nginx[‘proxy_set_headers’] = {
“X-Forwarded-Proto” => “https”,
“X-Forwarded-Ssl” => “on”,

external_url must include the https.