Cannot access local gitlab server GUI using browser

Problem Description

I have been running gitlab for the past couple of weeks using a computer running Ubuntu server 18.04. I have been having some problems in Gitlab I believe were caused by the external_url setting in /etc/gitlab/gitlab.rb

I tried to set external_url to the URL of a domain I own and was unable to access the GitLab servers login page, probably unsuprisingly. Prior to editing this I accessed GitLab through the LAN typing http://<server.local.IP>. I tried resetting the external_url with http://<server.local.IP>. But now I am unable to access the gitlab through the browser and simply get a refused to connect error message. Any help would be greatly appreciated I think from the outputs I included below (see useful information) GitLab is all running correctly I just cannot access the GUI through the browser. I have accessed the ubuntu server by logging in using ssh over the LAN.

Ideal Output Ideally I would like to be able to use the GitLab server outside the LAN so I can collaborate with others and use the compute resources of the server without being close the LAN. I have a static external IP address so should be able to port forward from port 80 or 22 of the server to a free port on the modem and then assign that a domain name.

Thanks for everyones help.

Useful Information

sudo gitlab-rake gitlab:env:info

Returns the following:

System information
System:		Ubuntu 18.04
Proxy:		no
Current User:	git
Using RVM:	no
Ruby Version:	2.6.5p114
Gem Version:	2.7.10
Bundler Version:1.17.3
Rake Version:	12.3.3
Redis Version:	5.0.7
Git Version:	2.24.1
Sidekiq Version:5.2.7
Go Version:	unknown

GitLab information
Version:	12.9.0-ee
Revision:	073a4ba8016
Directory:	/opt/gitlab/embedded/service/gitlab-rails
DB Adapter:	PostgreSQL
DB Version:	10.12
URL:		http://192.168.1.48 
HTTP Clone URL:	http://quessy.com/some-group/some-project.git
SSH Clone URL:	git@192.168.1.48:some-group/some-project.git
Elasticsearch:	no
Geo:		no
Using LDAP:	no
Using Omniauth:	yes
Omniauth Providers: 

GitLab Shell
Version:	12.0.0
Repository storage paths:
- default: 	/var/opt/gitlab/git-data/repositories
GitLab Shell path:		/opt/gitlab/embedded/service/gitlab-shell
Git:		/opt/gitlab/embedded/bin/git

sudo gitlab-ctl status

returns

run: alertmanager: (pid 30971) 1549s; run: log: (pid 4719) 6577s
run: gitaly: (pid 31014) 1548s; run: log: (pid 4710) 6577s
run: gitlab-exporter: (pid 31040) 1548s; run: log: (pid 4723) 6577s
run: gitlab-workhorse: (pid 5566) 1060s; run: log: (pid 4714) 6577s
run: grafana: (pid 5805) 1044s; run: log: (pid 4717) 6577s
run: logrotate: (pid 31091) 1547s; run: log: (pid 4722) 6577s
run: nginx: (pid 5775) 1044s; run: log: (pid 4721) 6577s
run: node-exporter: (pid 31200) 1546s; run: log: (pid 4715) 6577s
run: postgres-exporter: (pid 31206) 1546s; run: log: (pid 4718) 6577s
run: postgresql: (pid 31236) 1545s; run: log: (pid 4711) 6577s
run: prometheus: (pid 31245) 1545s; run: log: (pid 4720) 6577s
run: redis: (pid 31264) 1544s; run: log: (pid 4712) 6577s
run: redis-exporter: (pid 31269) 1544s; run: log: (pid 4716) 6577s
run: sidekiq: (pid 5621) 1056s; run: log: (pid 4713) 6577s
run: unicorn: (pid 6462) 1006s; run: log: (pid 4709) 6577s