I cant dual-boot PureOS


I install PureOS (from a DVD) activating legacy boot on my HP laptot (15-bs021la) that have Windows 10, but now I cant select PureOS, I dont have GRUB and I dont know how to do that PureOS have EFI compability. I tried do a boot repair with boot-repair-disk and all the time get an error cause troubles with GRUB and EFI files. Anyone can help me? Thank you and sorry for my english.