It is possible to configure in this way.
You can customize the forgot password email template to display the generated changePasswordId rather than using it as part of the URL.
Two pages will need to be customized for the theme:
Forgot password sent - update this to forward the user to the “Change password form” page. One option to perform this redirect is to use a meta refresh tag Change password form - the default template uses a hidden element to submit the changePasswordId. You can use another form field that the user fills out to submit the code.FusionAuth hosted pages will require the verification code and updated password to be submitted on the Change Password form page.
Please also note the potential security implications of shortening the verification code to 4 digits instead of the default 32 encoded bytes.