virtualbox – Access MailHog WebGui Running in Virtual Machine from Host Machine’s Web Browser

I have a Debian 10.5 LAMP server in virtualbox 6.1, running with ISPConfig and Roundcube.

I installed MailHog to test my email configs, however MailHog’s webGUI is only available on:
localhost:8025 and/or 127.0.0.1:8025

How can I change the address of MailHog’s webGUI to match the ip of my virtualmachine? For example:

test.example.com:8025and/or 192.138.87.100:8025

I’ve read the docs at:
https://github.com/mailhog/MailHog/blob/master/docs/CONFIG.md

but, I must be missing something.. (zero coding skills)