It looks like the environment variables are not being mapped correctly as mentioned in the docs. You can check this link to set the correct values for environment variables (DESIGNER_ROLE_ID, ANONYMOUS_ID, CLIENT_ROLE_ID, REVIEWER_ROLE_ID, USER_RESOURCE_ID) either using postman or curl method. This will ensure the form submission works correctly.
In formsflow.ai we are using formio to create and manage forms. The environment variables which are missing are necessary for forms to be submitted correctly. Also ensure you have correctly done the forms-flow-forms setup and then proceeded to forms-flow-web setup.