Welcome emails sent by Frappe framework are missing the port number

When using Frappe framework and changing the Nginx port from 80 to 8002 to avoid conflicts, I get broken URLs in all emails sent by the system. The port was changed using bench set-nginx-port 8002. The ports 80 and 8000 are already busy in the VPS.

While I access the system using hostname:port_number, I get all emails as hostname/the-rest-of-url.

The same issue was reported on frappe.io and GitHub, but it's unclear how to solve it.

How can I solve this? Thank you in advance!

Open site_config.json and write "hostname":"http://<your_hostname>:<your-port-number>". For example:

{
 "db_name": "your_db_name",
 "db_password": "your_db_password",
 "db_type": "your_db_type",
 "hostname": "http://your_host_name:port_number"
}