installed self hosted on Ubuntu 18.04 with self signed ssl. cant get past setup

hi
I followed instructions here: https://www.linuxbabe.com/ubuntu/install-invoiceninja-ubuntu-18-04-apache-nginx#comment-33665 (including the installing LAMP Stack on 18.04) and everything went well right till the end.
I did use this tutorial (https://hostadvice.com/how-to/how-to-install-a-self-signed-ssl-certificate-for-apache-on-ubuntu-18-04-server/) for installing a self assigned ssl certificate as I am running this as a localhost machine only via the local ip address.
I tested the database connection and sent a test email. both work okay.
when I click submit on the final setup page, it comes up and says unable to connect/problem loading page.
what am I doing wrong?
please help

Are there any details in storage/logs/laravel-error.log or the web server error log?

Very new to Ubuntu. How would one check this log file in Ubuntu 18.04?

https://askubuntu.com/a/14767

As an aside, if you’re only going to be accessing it from the local IP address and nobody outside of your network will be using it, then SSL isn’t even necessary.