Create a web form model

Question

I’m putting together a web page with . Net Core and I have a web form that has many fields and I was thinking about how to get all this information filled out more dynamically, I asked a question here and they gave me the suggestion to make a model to get this information, but I’m a beginner and I don’t know how to do it, I already did a search and started too, but I’m getting all the values null, I’ll leave +/- as is my code, please help me.

MODEL:

public class Persist
{
    public string[] data {get;set;} = {};
}

I left just one example, so it doesn’t get long, if I understand one, I try to do the others myself.

FORM:

<form method="POST">
    <select class="form-control w-100" id="data2" name="data[2]">            
        <option value="N"> Não analisar</option>            
        <option value="S"> Sim</option>        
    </select>

    <select class="form-control w-100" id="data5" name="data[5]">            
        <option value="N"> Não analisar</option>            
        <option value="S"> Sim</option>        
    </select>

    <select class="form-control w-100" id="data8" name="data[8]">            
        <option value="N"> Não analisar</option>            
        <option value="S"> Sim</option>        
    </select>
</form>

Function that picks up the data:

private static string Save(Models.Persist p)
{
    var teste = p.data[2]; // Dá erro

    return teste;
}

When I debug the code and try to see the value of p (the Model), all variables appear, but all variables null, how do I get the value of the fields?

I’m a beginner.

Grateful.

EDIT:

With the modification of model, the value of data now appears {string[0]}