It is clearly specified that the maximum memory extension is 256GB, i.e. the capacity of the device with its internal memory. If expansion were possible, this figure should be higher. With rigorous management of storage space, regular clean-ups and occasional reboots, this is sufficient. You can always opt for cloud storage or an external hard drive if you need to.

...not possible at all, specification is somewhat misleading... There is 256 GB of internal memory in this model, more is not possible.