Validation is_unique cannot be configured with dot_syntax

How do I check the array of values (mark)?

PHP Code:

        [
            '*.mark' => [
                'label' => 'App.link.mark',
                'rules' => 'required|is_unique[link.mark,mark,{mark}]',
            ],
            '*.url' => [
                'label' => 'App.link.url',
                'rules' => 'required|min_length[7]|max_length[255]',
            ],
        ]; 


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