hi rsu and welcome to Mageia.
during install, did you, during the boot options enter a password for the bootloader?
this after you enter the root /admin and user passwords and user name
If you did, I am unsure how to disable the password for the bootloader.
If you have just completed the install, you could re-run the install and leave the bootloader password field blank.
have a look here section :
http://mirror.aarnet.edu.au/pub/mageia/ ... akX-en.pdf, section 23.1.1. Grub2 on Legacy/MBR and Legacy/GPT systems
(from
https://www.mageia.org/en/doc/Mageia 6
Online manual for Installer available in English
(also as file: PDF, EPUB) ) and choose (pdf)