How do I host a Matrix server on a VPS?

sudo apt install -y lsb-release wget apt-transport-https
sudo wget -O /usr/share/keyrings/matrix-org-archive-keyring.gpg https://packages.matrix.org/debian/matrix-org-archive-keyring.gpg
echo "deb [signed-by=/usr/share/keyrings/matrix-org-archive-keyring.gpg] https://packages.matrix.org/debian/ $(lsb_release -cs) main" |
    sudo tee /etc/apt/sources.list.d/matrix-org.list
sudo apt update
sudo apt install matrix-synapse-py3

sudo apt install postgresql libpq5
sudo -u postgres createuser --pwprompt synapse_user
sudo -u postgres createdb --encoding=UTF8 --locale=C --template=template0 --owner=synapse_user synapse

# /etc/matrix-synapse/conf.d/database.yaml
database:
  name: psycopg2
  args:
    user: synapse_user
    password: CHANGE_ME
    dbname: synapse
    host: localhost
    cp_min: 5
    cp_max: 10

# nginx: inside a server block that listens on 443 ssl for matrix.example.com
location ~ ^(/_matrix|/_synapse/client) {
    proxy_pass http://localhost:8008;
    proxy_set_header X-Forwarded-For $remote_addr;
    proxy_set_header X-Forwarded-Proto $scheme;
    client_max_body_size 50M;
}

# Synapse listener on port 8008, in homeserver.yaml or a conf.d file
listeners:
  - port: 8008
    type: http
    x_forwarded: true
    bind_addresses: ['127.0.0.1']
    resources:
      - names: [client, federation]

# conf.d/registration.yaml  (a random value, kept secret)
registration_shared_secret: "RANDOM_VALUE"

sudo systemctl restart matrix-synapse
register_new_matrix_user -c /etc/matrix-synapse/homeserver.yaml