By default, WP Travel plugin takes the admin email address from the email set in the Site Admin’s email address set in Admin Dashboard > Settings > General.
Screenshot: https://prnt.sc/kr683b
Please make sure to check the e-mail set in the settings ( also in spam folders ) to check for e-mails.
Also, The feature to set admin e-mail alerts to custom e-mails is already available in our WP Travel Utilities Addon.
With WP Travel Utilities Addon, you can set custom e-mails for bookings, payments and inquiries alerts.
To learn more about this and other exciting features of WP Travel Utilities addon, please check the URL here :
http://wptravel.io/downloads/wp-travel-utilities/
Best Regards !!