When do you want to access it? Typically, the FindControl method is used when accessing controls within Data Representation controls or wthin a naming container hierarchy.

Here's an example for accessing it at RowDataBound event of GridView:

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e) {
            if (e.Row.RowType == DataControlRowType.DataRow) {
                LinkButton link = (LinkButton)e.Row.FindControl("lnkBtnEditRequest");
                //do something with the link here
            }
}

You can also access the control outside RowDataBound event after the GridView is binded with data.

//accessing specific control
// just change the index of cells based on your requirements 
LinkButton link = (LinkButton)GridView1.Rows[0].Cells[0].FindControl("lnkBtnEditRequest");


//if you want to access multiple rows then you can loop through the gridview rows and then do the findcontrol within your loop