Can't log in after closing HA after initial installation - Raspberry Pi 3

I installed HA as per the webpage. All went fine. I set up username and password, etc - minimum install and logged out. I went to the URL to log in again. The HA login screen appeared asking for username and password. I entered it and I get invalid username or password.

I flashed the SD card and inserted into the Raspberry Pi. All went well again. I logged off and reopening using URL. HA asked for username and password. I entered them and again I get invalid username or password.

The url I’m using is http://homeassistant:8123/. It finds the Raspberry Pi

What am I missing?

Thanks!