You did not set booking page correctly in theme options panel.
Please check http://prntscr.com/qvgstq and http://prntscr.com/qvgt9p
You should read description carefully for booking flight page field in theme options panel.
So when i go to book a flight, it does not redirect me to the booking page.
Please tell me more details about your issue.
And give me your website url and admin credentials.
Flight booking is still not working