The common portal for generation of e-way bill is E-Way Bill Portal
Please check if you have activated ‘Do Not Disturb (DND)’ facility on your mobile or your service provider network may be busy. You can also use OTP, which is sent on your email-id.
Please check your internet connectivity.
Please check whether your system has proper version of the browser as suggested by the e-way bill portal and also check the security settings of the browser and display property of the system.The site is best viewed on Internet Explorer 11 or above, Firefox 43.5 or above and Chrome 45 or above.