Event of button in Header template in Grid view

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C#

I am using a Gridview and placing a button inside the header template.
But i am unable to get it's click event. Can anyone look into it and guide me? My code is:

<asp:gridview id="gvReviewRequest" allowpaging="True" onrowcommand="ProductsGridView_RowCommand" xmlns:asp="#unknown">
            AutoGenerateColumns="False" runat="server"&gt;
            <columns>
                <asp:templatefield headertext="Price">
                    <itemtemplate>
                         <asp:label id="lblStatus" runat="server" text="&lt;%# Eval("Status") %&gt;"></asp:label>
                    </itemtemplate>
                </asp:templatefield>
                <asp:templatefield>
                <headertemplate>
                <asp:button runat="server" id="IncreaseButton" text="Increase Price 5%" commandname="Increase">
                           /&gt;
                </asp:button></headertemplate>
                    <itemtemplate>
                        
                    </itemtemplate>
                </asp:templatefield>
            </columns>
        </asp:gridview>