Hello, I build a List button that Includes a Visualforce Page. When I chose Accounts in List view and click account I only see the blank Page without the account fields. Please tell me how to change it.

<apex:page standardController="Account" renderAs="pdf" recordSetVar="accounts" >
 

<h1>Welcome to APP!</h1>
 
<p>Thank you, <b><apex:outputText value=" {!Account.Name}"/></b>, for 
   working with APP.</p>
 
<p>Your account details are:</p>
 
<table>
<tr><th>Account Name</th>
    <td><apex:outputText value="{!Account.Name}"/></td>
    </tr>
<tr><th>Account Rep</th>
    <td><apex:outputText value="{!Account.Owner.Name}"/></td>
    </tr>
<tr><th>Customer Since</th>
    <td><apex:outputText value="{0,date,long}">
        <apex:param value="{!Account.CreatedDate}"/>
        </apex:outputText></td>
    </tr>
</table>
    
</apex:page>



Result: