I was running frappe from one of my ubuntu computers and wanted to access website through my other windows computer. Couldnt find anything on internet thats why posting it as a solution.
Firstly get you local ip by typing "ifconfig (in terminal) it will look like 192.168.xx.xxx
then just enter these lines in base frappe/erpnext folder (by firstly changing 192.168.xx.xxx to your own ip)
ufw allow 8000
ufw allow tcp/8000
bench new-site 192.168.xx.xxx
bench --site 192.168.xx.xxx add-to-hosts
bench --site 192.168.xx.xxx install-app erpnext
then just visit 192.168.xx.xxx:8000 from any network computer and it will work fine!