PayPack supports adding a Payment link to NetSuite's Advance PDF/HTML template. This type of template is found under Customization > Forms > Advance PDF/HTML Templates.   

To add the Payment Link Field to this form:

1. Open the form you would like to add the payment link too 
2. Navigate to the section where you want to add the payment link
3. Click the "plus" button
4. Search for "PayPack Payment Link" or "PayPack Payment Link (Plain Text)"

If you would like to add a Payment Link to a button, you will need to add the field ID, custbody_nm_stripe_charge_pt_lnk_plain, to the source code of your document:

This is an example of the document when it is ready to be sent:

To simply display a click here to pay link, use the sample syntax.

<#if record.custbody_nm_stripe_charge_pt_lnk_plain?has_content>
  <a href="${record.custbody_nm_stripe_charge_pt_lnk_plain}" rel="link">Click Here to Pay</a>undefined
</#if>

To display a pay now button, use the sample syntax.

<#assign rawLink=record.custbody_nm_stripe_charge_pt_lnk_plain>
<#assign paymentLink=rawLink?replace('.*href="([^" ]+)".*', '$1' , 'r' )>
    <table class="payhere" style="width: 100%; margin-top: 10px; margin-bottom: 20px;">
      <tr>
        <td align="left" style="text-align:center;">
          <div style="margin-left: 0px; padding: 0px 20px; display: inline-block; background-color: #635BFF; color: white;  font-weight: bold; border-radius: 5px !important; font-size: 18px;">
            <a href="${paymentLink}" style="text-decoration: none;">Pay Now</a>
          </div>
        </td>
      </tr>
    </table>

To display the PayPack customer portal link instead of a payment link for customers with a recurring payment schedule, use the below NetSuite PDF/HTML form syntax.

<#if record.entity.custentity_nm_stripecharge_pay_schedule=="Recurring">
  <a href="${record.entity.custentity_pp_stripe_cust_port_lnk}" rel="link">Click Here to Update Payment Method</a>
  <#else>
    <a href="${record.custbody_nm_stripe_charge_pt_lnk_plain}" rel="link">Click Here to Pay Invoice Online</a>undefined
</#if>