Email not working with Version 3

I am using calender in my website to take orders. I am only using PINPOint booking system Pro version with Version 3.(Pinpoint Booking System WordPress Plugin 3.X)

I am using Brevo as my smtp and when I select SMTP setting, I see the order is not getting created. Debug log shows below error.

Stack trace: 0 /var/www/wp-content/plugins/pinpoint-booking-system/application/models/_platform/reservations/notifications/model-reservation-notifications-email.php(942): DOTModelReservationNotificationsEmail->smtp(Array) 1 /var/www/wp-content/plugins/pinpoint-booking-system/application/ajax/calendar/ajax-calendar.php(207): DOTModelReservationNotificationsEmail->send(‘rsr68354e7cb678…’, ‘book-approval’) 2 /var/www/wp-includes/class-wp-hook.php(324): DOTAjaxCalendar->book(”) 3 /var/www/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(”, Array) 4 /var/www/wp-includes/plugin.php(517): WP_Hook->do_action(Array) 5 /var/www/wp-admin/admin-ajax.php(192): do_action(‘wp_ajax_pbs_cal…’) 6 {main}

thrown in /var/www/wp-content/plugins/pinpoint-booking-system/application/models/_platform/reservations/notifications/model-reservation-notifications-email.php on line 1033

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