simple dynamic dropdown

Good morning, i know that is a hot topic🙂 and I have read the FAQ but my dropdown don't Work !!!
Where is my mistake?
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My setup:

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My design
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My setup conf
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My dropdown conf:
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The dropdown is empty...😟 I used {var:read_data5.cognome} too !😟
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Help me!

Hi cyber81,
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Sorry, but I can't read anything useful in any of your images.
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Bob

Put a debug action in at the end of your load action. to help make sure you actually have something in that read_data

Array
(
    [format] => html
    [Itemid] => 1038
    [option] => com_chronoforms6
    [view] => form
)

Array
(
    [read_data5] => Array
        (
            [log] => Array
                (
                    [0] => SELECT `data5`.`aid` AS `data5.aid`, `data5`.`cognome` AS `data5.cognome` FROM `ifr76_chronoforms_6_data_asti-inserimentolavoratore` AS `data5` LIMIT 100;
                )

            [var] => Array
                (
                    [9] => Forte
                    [13] => Pallino
                )

        )

)

Now i want that data5.cognome (in this case Forte e Pallino) will be listed in dropdown..
At the dropdown conf I have put in Option {var:read_data5.cognome}

I resolved it; on setup the "read data" must be put before display....