Grub has been installed but I dont see it on boot so cant dual boot

[omano]

@codetemplar

Warning: os-prober will not be executed to detect other bootable partitions.
Systems on them will not be added to the GRUB boot configuration.
Check GRUB_DISABLE_OS_PROBER documentation entry.

Did you read your screen?

One of many available information source about this

@philm

If you need dual-boot you can reactivate os-prober the easiest with the following command combination in a terminal:

echo GRUB_DISABLE_OS_PROBER=false|sudo tee -a /etc/default/grub && sudo update-grub