Export the model as a .java file that Minecraft understands. This blender-addon provides buttons for exactly those three actions: Button to add a new box mesh to the scene. Button to set the UV layout ...

Blender is a popular and powerful 3D modeling software that is free and open source. It supports a wide range of formats for importing and exporting 3D models, such as FBX, OBJ, STL, GLTF, DAE ...