I have a Sandisk Extreme 128GB, my intention is to use for my music library on Macbook Pro (Mojave). I would prefer to use it encrypted but have run into issues with disk utility. The option to partition is greyed out in disc utility and the option to encrypt in Finder is not there at all. It is currently formatted as Mac Os Extended journaled, but reformatting from here still does not give access to any mapping options. I have attached pictures that are hopefully illustrative. I have also attempted all above with Normal SD card adaptor and the Sandisk usb adaptor. Any help is much appreciated.