HOW TO PASS VALUE USING SERVER.TRANSFER

check this

protected void Linkbutton1_Click(object sender, EventArgs e)
{
HttpContext CurrContext = HttpContext.Current;
CurrContext.Items.Add("Name", "Shawpnendu Bikash Maloroy");
CurrContext.Items.Add("Address", "Dhaka, Bangladesh");
Sever.Transfer("Destination.aspx");
}

In Destination.aspx Page under Load event write the below code:

protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
HttpContext CurrContext = HttpContext.Current;
Response.Write(CurrContext.Items["Name"].ToString()+" ");
Resonse.Write(CurrContext.Items["Address"].ToString());
}
}

If you are using Server.Transfer to redirect and not disabling PreserveForm property, previous page controls details are available through Page.PreviousPage Property[^]. If you need to specifically pass something through querystring, you can still do that. Just add querystring at the end and you can access that in the redirected page.

You may want to read this MSDN article as well: Cross-Page Posting in ASP.NET Web Pages[^]