How to send the request from one razor page to another

Quote:

An unhandled exception occurred while processing the request.
NullReferenceException: Object reference not set to an instance of an object.
testCRM.Pages.Leads.Pages_Leads_List.<executeasync>b__9_0() in List.cshtml, line 0

Quote:

When i am clicking on the leads button. I am getting above error.

@page
@model testCRM.Pages.Users.ListModel
@{
}
<h2>List of employess</h2>
<h3>@HttpContext.Session.GetString("Message")</h3>

<form>
    <table border="1">
        <tr>
          <td><a asp-page="/Leads/List">Leads</a></td>

        </tr>
    </table>
<table>
    <tr>
        <th>User FName</th>
        <th>User LName</th>
        <th>User EMAIL</th>
        <th>Action</th>
    </tr>
    @foreach(var User in Model.User)
    {
        <tr>
            <td>@User.UserFName</td>
            <td>@User.UserLName</td>
            <td>@User.UserEmail</td>
             <td><a asp-page="Update" asp-route-id="@User.ID" class="linkbutton">Update</a></td>
             <td><a asp-page="Delete" asp-route-id="@User.ID" class="Linkbutton">Delete</a></td>
        </tr>
    }
</table>
</form>

@page
@model testCRM.Pages.Leads.ListModel
@{
    <form method="post">
      <table>
      <tr>
        <th>Name</th>
        <th>Status</th>
        <th>CompanyName</th>
        <th>EmailAddress</th>
        <th>Phone</th>
        <th>AssignUsers</th>
         <th>CreateDate</th>
      </tr>
      
       @foreach(var item in Model.Leads)
            {
              
                <tr>
                <td>@item.FIRST_NAME</td>
                <td></td>
                <td></td>
                <td>@item.EMAIL1</td>
                <td>@item.PHONE_MOBILE</td>
                <td>@item.ASSIGNED_USER_ID</td>
                <td></td>
                </tr>
            }

      </table>
    </form>
}