Hello,
Nice job getting it set up so that users can only purchase one ticket at a time! To change the button, you could do a template override of the tickets.php file found at wp-content/plugins/event-tickets-plus/src/views/wootickets. Look for this around line 205:
<td colspan="4" class="woocommerce add-to-cart">
<?php if ( $must_login ) : ?>
<?php include Tribe__Tickets_Plus__Main::instance()->get_template_hierarchy( 'login-to-purchase' ); ?>
<?php else: ?>
<button
type="submit"
name="wootickets_process"
value="1"
class="tribe-button"
>
<?php esc_html_e( 'Add to cart', 'event-tickets-plus' );?>
</button>
<?php endif; ?>
</td>
We are a bit limited in the amount of support that we can provide for customizations, but if you get stuck or have any questions, please let me know – I’ll be happy to point you in the right direction!