This is a custom plymouth theme that let you change your native splash boot...

I am linux user and actually my computer handle linux lite (xfce)
Because of that i dont know if you can put this theme in the same way (maybe you have to google it)
in gnome, you have to copy amaze folder with administrative mode to /usr/share/plymouth/themes
then you open the terminal and run this (you can copy and paste on terminal) :

sudo ln -sf /usr/share/plymouth/themes/amaze/amaze.plymouth /etc/alternatives/default.plymouth

sudo update-initramfs -u