Beelink BT3 does not start

mikiego

Hi
probably I've made something incorrect.
I've tried to install Daphile on Beelink BT3.
During the final phase of the installation, I deselected the UEFI option, under suggestion of a Daphile expert.
I'm not sure if this is the problem or if it was the installation itself that caused it. Now the computer is stuck on the initial screen and I can't access the BIOS.
Since Daphile is a screenless installation, I must mention that the address assigned to Daphile seems to be occupied, but I can't access it: I get the message
"Your browser is not supported. Use the latest version of the browser to access the web interface." My browser is up-to-date, of course.
How can I access the PC, the BIOS, boot from an external operating system, for example with an Ubuntu live CD, even to completely format the disk and start over from scratch?
Thank you for your help.
Michelangelo