Your email address is your unique identifier. Therefore it is not possible to change it.
If you don't have access to your email address, withdrawing funds from your account would be unavailable as each withdrawal is confirmed via email.
How to prevent this issue from happening
It's important to keep track of your email address on a regular basis, don't leave it unattended, some email providers may deactivate unused addresses and issue them once again. It's a good idea to use trusted and proven email providers like Gmail, Outlook, etc.
Furthermore pay attention to your email security. As it is the key to your exchange account, make sure to take appropriate security measures. Please protect your account with 2FA and change your password on a regular basis.
How to resolve this issue
Contact your email provider support team, usually lost email accounts can be restored.
If there is no way for you to restore access to your email account, please contact us by tapping the chat icon on the bottom right of the screen.