Thanks,
Can we use javaScript and update the value for the paypal payment when we update the first two custom input field?
<label for="custom" class="wppaypal_buynow_custom_amount_label">Invoice number or reference:</label>
<input class="wppaypal_buynow_custom_amount_input" type="text" name="custom" id="customInvoice" value="" required=""/>
<br />
<label for="amount" class="wppaypal_buynow_custom_amount_label">Enter the amount (GBP):</label> <input class="wppaypal_buynow_custom_amount_input" type="text" name="amount" id="customAmount" value="" required=""/>
[wp_paypal_checkout button="buynow" description="test checkout product" amount="3.99"]