How can i do two UV maps in one mesh?

I have a mesh. Sphere, for example.
The first thing I want to do is UV mesh sizes (it means that it will be not packed in a cube 1 by 1 meter).

Then the second UV will be packed in a cube of 1 meter by 1 meter (in UV editor).

After that, I need to make a GLTF file, where my mesh will have 2 ready-made and different UV saved in one file. Is it possible? If so, I would be grateful if you could tell me how to do it through UV editing and shading.

Add a second uv in the object data properties tab

I found it here.
Screen Shot 2022-02-10 at 8.50.19 PM
Just put the " + " button.