Then I exported the fbx file like this. Like everyone else does when using skinned meshes:
Then I get inside studio, opened the Avater Importer plugin (by Roblox) then imported the fbx file. When it gets inside workspace, you can see the texture is not the same as it was in blender before getting imported to roblox.
Import the mesh without the texture, you know with the usual gray color. Then, save the texture as a .png in your PC. Create a texture inside your mesh and upload the texture image from your desktop/file location.
all of them so when you have clicked localise in the box on the bottom left of your screen then tick all options there there should be an option to tick something like rotation and scaling.