Upload fbx in blender , Export in gltf/glb/obj (I would use obj) and upload it in godot (exported) then load the textures in a separate folder and try to put the textures on the model, Normaly that should work , (glb gives godot a warning but works normaly)
In Godot 4.3 you can directly import .fbx files. Then create a new inherited scene from them. Select your new scene and click on surface material override. Under albedo drop the png texture file. No need to import in blender.
