Showing warning in register_setting

I am facing a warning in the following code. Tell me why the plugin check is showing a warning. I want to remove this warning.

register_setting(
    'vendor_cutom_field',
    'vendor_cutom_field_call_back_func',
    array(
        'type' => 'string',
        'sanitize_callback' => 'sanitize_text_field',
    )
);