Register your webpart at the top of the page using sample code below
<%@ Register tagprefix="VotingButton"
namespace="xx.org.SharePoint.WebParts.VotingButton"
assembly="xxx.org.SharePoint, Version=1.0.0.0, Culture=neutral,PublicKeyToken=ff75f32512e6d74c" %>
Next, add the web part to the web part zone area of page as below
<VotingButton:VotingButton runat="server"
Description="VotingButton"
Title="VotingButton"
__MarkupType="vsattributemarkup"
__WebPartId="{58eb6642-70ed-450e-af72-e6062d07da2f}"
WebPart="true"
__designer:IsClosed="false"
partorder="2"
id="g_58eb6642_70ed_450e_af72_e6062d07da2f">
</VotingButton:VotingButton>