Submit Button Not Working

Hi, I am happy to use your plugin but I tried sending one form but the submit button is not working. I already fill in all the require fields but the button is still not working. it clicks but nothing happens, no error or any thing. please see the link so you can try it out for yourself (https://www.sabai-sabai-sukhumvit.com/main/reservation)

https://www.ads-software.com/plugins/planso-forms/