How to add a column “EAN” with an editable text field to an automatically generated Variations Grid in a configurable product?

I can add column EAN here:
MagentoConfigurableProductUiDataProviderProductFormModifierConfigurablePanel
inside method getRows() like this

'ean_code_container' =>   $this->getColumn(
        'ean_code',
        __('EAN Code')          
    );

The field is shown and I can input data. But data does not save!