ssd card not letting me format

[kiwi334334]

chromebook acer spin 11 (511-1h)
I have a apollo-lake model.
i am running a ISO method with a small 8GB usb drive and a 256GB ssd card.
the problem is after i use all the steps i can find online I use the 8GB usb to install the ISO, I go into the GalliumOS desktop then i double click on the icon to install and go with english then click on install third party apps and then click on something else then i go and find my ssd card but it dosent let me format the ssd card so i dont know what to do and im scared for my chromebook