Thank you very much friend for the reply.
I am not sure whether I clicked nonfree drivers. But I used Rufus to burn the ISO to pendrive. I’ll try again following your instructions. I will let you know if some problem occurs after installation. Thank you very much friend for your help.
Thank you very much for your reply friend.
1) product name : HP Laptop 15-da0xxx
BIOS version: F.36
Processor type: i7-8550U @ 1.80GHz
BIOS mode: UEFI
2)These errors occurs when trying to install Ubuntu using bootable pen drive. Exactly when click the Ubuntu(safe graphics)...