Auto restart the server after capistrano deploy

I have nginx + nginx unit + django python application , and django project is is deployed by capistrano

deploy.rb

lock "~> 3.16.0"

set :application, "mynavi"
set :branch, 'master'
set :deploy_to, "/var/www/html/mynavi"

set :linked_dirs, fetch(:linked_dirs, []).push('static')
set :keep_releases, 3

set :linked_files,  %w{.env}

set :repo_url, "ubuntu@git.example.jp:/~/myGit/mynavi.git"

production.rb

set :stage, :production
set :branch, 'master'
server 'lion.example.jp', user: 'ubuntu', roles: %w(app), primary: true
namespace :deploy do
    desc 'Collec Static Files'
    task :collectImg do
        on roles(:app) do
            execute "source activate mynavi;/home/ubuntu/anaconda3/envs/mynavi/bin/python /var/www/html/mynavi/current/manage.py collectstatic --noinput"
        end
    end
    after :publishing, :collectImg
end

cap prodution deploy makes deployment successfully

However, after deployment

I need to restart unit manually.

sudo systemctl restart unit

Can I do this automatic after deployment?

---

Solution

Thanks to @Timo Stark 's answer

My final production.rb is here, just adding the curl line.

production.rb

set :stage, :production
set :branch, 'master'
server 'lion.example.jp', user: 'ubuntu', roles: %w(app), primary: true
namespace :deploy do
    desc 'Collec Static Files'
    task :collectImg do
        on roles(:app) do
            execute "source activate mynavi;/home/ubuntu/anaconda3/envs/mynavi/bin/python /var/www/html/mynavi/current/manage.py collectstatic --noinput"
            execute "sudo curl -X GET --unix-socket /path/to/control.unit.sock http://localhost/control/applications/app_name/restart"
        end
    end
    after :publishing, :collectImg
end

With the latest release you are able to restart the application and let Unit reload the code from the workdir.

sudo curl -X GET --unix-socket /path/to/control.unit.sock  \
      http://localhost/control/applications/app_name/restart

https://unit.nginx.org/configuration/#process-management

Happy to discuss the capistrano intergration a little further.