WordPress nested block variation

I have two blocks parent and child. I would like to create variation of both of them (parentV and childV) and have the childV as inner block of the parentV. But when I try it with registerBlockVariation() I am getting error, that childV does not exists. Is there something special I need to do for childV variation registration.

Example what I have

{
  "name": "child",
  "title": "Child",
  "parent": ["parent"]
}

{
  "name": "parent",
  "title": "Parent"
}

Parent has the child in allowedBlocks.

Then I have TS

domReady( function () {
  registerBlockVariation( 'child',
    {
      name: 'childV',
      title: 'ChildV',
      attributes: {
        className: 'child-v',
      },
    }
  );

  registerBlockVariation( 'parent',
    {
      name: 'parentV',
      title: 'Parent V',
      attributes: {
        className: 'parent-v',
      },
      innerBlocks: [
        {
          name: 'childV',
        },
      ],
    }
  );
});

• Am I missing something?
• Is it event possible to create variations like this?

Thank you for help 🙂