Get ID from item wich is checked from checkbox in ASP.NET Core 5 MVC

I need help! I have an ASP.NET Core 5 MVC Webapplication. I have a list with items from a .mdf-database and want at the end of a item-row a checkbox. When I am in the controller of this view, I want to have the ID of the item, which is checked. There could be more checked. But I don't know how to to this. Below some snippets from my code:

Index.cshtml

<form asp-action="Send">
    <table class="table">
        <thead>
            <tr>
                <th>
                    @Html.DisplayNameFor(model => model.Id)
                </th>
                <th>
                    @Html.DisplayNameFor(model => model.Bez)
                </th>
                <th></th>
                <th></th>
            </tr>
        </thead>
        <tbody>
            @foreach (var item in Model)
            {
                <tr>
                    <td>
                        @Html.DisplayFor(modelItem => item.Id)
                    </td>
                    <td>
                        @Html.DisplayFor(modelItem => item.Bez)
                    </td>
                    <td>
                        <a asp-action="Edit" asp-route-id="@item.Id">Edit</a> |
                        <a asp-action="Delete" asp-route-id="@item.Id">Delete</a>
                    </td>
                    <td>
                        @Html.CheckBox("Finalized", false)
                    </td>
                </tr>
            }
        </tbody>
    </table>
    <input type="submit" value="Send" class="btn btn-primary" />
    <br /><br />
    <p>Achtung! Beim Senden an einem Freitag wird der Dienstplan automatisch für den darauffolgenden Montag eingeteilt.</p>
</form>

Can someone help me? I just want the id's in a list in my controller, which are checked.