Structure Blocks Not Saving To Disk Or Separate File

Structure blocks do not save structures to a separate file when saving to disk and 3D exports are not saving as .mcstructure. If this is intended, make a way to load a structure block from your computer and maybe even on other people's worlds from your computer. I try to save to disk from my switch to my computer but it doesn't work. Then from my phone to my computer and it doesn't work. Then I try from a local world in my computer and it still doesn't work. There are no files popping up from saving to disk and there is no way to transfer between worlds that I know of.