Running Hookshot on homeserver with nginx

Hi! I am trying to setup Matrix Hookshot on my homeserver. I am currently running Matrix Synapse and Gitea on it. I am also using Nginx as a reverse proxy for both. I would like to use Hookshot to receive notifications on my Matrix server whenever commits are pushed.

I have been trying to setup Hookshot during the weekend, but I am hitting a brick wall. When starting Hookshot I get the following errors:

ERROR 08:17:15:143 [MatrixHttpClient] (REQ-1) Error: connect ECONNREFUSED ::1:8008
    at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1481:16) {
  errno: -111,
  code: 'ECONNREFUSED',
  syscall: 'connect',
  address: '::1',
  port: 8008
}
ERROR 08:17:15:145 [Appservice] Encountered error registering user: 
ERROR 08:17:15:145 [Appservice] Error: connect ECONNREFUSED ::1:8008
    at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1481:16) {
  errno: -111,
  code: 'ECONNREFUSED',
  syscall: 'connect',
  address: '::1',
  port: 8008
}
WARN 08:17:15:146 [Bridge] Failed to connect to homeserver, retrying in 5s Error: connect ECONNREFUSED ::1:8008
    at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1481:16) {
  errno: -111,
  code: 'ECONNREFUSED',
  syscall: 'connect',
  address: '::1',
  port: 8008
}

My config.yml file (only relevant parts of it) with the domain masked as mydomain.com:

bridge:
  domain: mydomain.com
  url: http://localhost:8008
  port: 9993
  bindAddress: 127.0.0.1
listeners:
  - port: 9000
    bindAddress: 127.0.0.1
    resources:
      - webhooks

My registration.yml:

id: matrix-hookshot
as_token: MyAsToken
hs_token: MyHsToken
namespaces:
  rooms: []
  users:
    - regex: "@_webhooks_.*:mydomain.com"
      exclusive: true

sender_localpart: hookshot
url: "http://localhost:9993"
rate_limited: false

My Appservice file:

id: matrix-hookshot
url: http://localhost:9993
as_token: MyAsToken
hs_token: MyHsToken
sender_localpart: hookshot
namespaces:
  users:
    - exclusive: true
      regex: "@_gitea_bridge_.*"
  aliases: []
  rooms: []

I have tried the following:

Use https instead of http (nginx is set up to only accept HTTPS connections so thought that could be the reason)
Use my domain name instead of localhost
Use 127.0.0.1 instead of localhost
Run curl http://localhost:8008/ and curl http://127.0.0.1:8008/; both succeed and return expected HTML redirecting to http://localhost:8008/_matrix/static/
Run curl -6 "http://[::1]:8008"/ fails with the same error reported by Matrix Hookshot

I am quite a newbie to this, so I also struggled a bit with the documentation. I would like to understand what I'm doing wrong so I can write a guide for non experienced users as I can't find one and it's something I feel I am missing throughout my attempts.

matrix-org / matrix-hookshot

Running Hookshot on homeserver with nginx #829