I don’t know if this is just a quick hack or something you can use on your end for the update. But I got some help and implemented this……
Find in /wp-content/plugins/wp-invoice/lib/ui/profile_page_content.php
<table class="form-table" ><tr>
<th><h3><?php _e('Billing / Invoicing Info', ud_get_wp_invoice()->domain) ?></h3></th>
<td>
<input type="button" onclick="window.location.href='<?php echo $wpi_settings['links']['manage_invoice'].$email; ?>'" class="button" value="<?php echo __('Send New Invoice', ud_get_wp_invoice()->domain) ?>" id="crm_new_invioce"/>
</td>
</tr>
</table>
Edit
1. Add this before the <table> tag:
<?php if ( current_user_can('administrator') ) : ?>
2. Add this after the </table> tag:
<?php endif; ?>
After all said and done only the admin can see that Send New Invoice Button.