restaurants aren't added to the vendors

Describe the bug
upon filling the registration form the page doesnt render anywhere or save any changes to data after clicking save

To Reproduce
Steps to reproduce the behavior:

Go to 'vendors'
Click on 'Add restaurants'>>fill form
Scroll down to 'save' and click
See error
Expected behavior
data should be saved with a success prompt

image

upon clicking the following happens:
image

Desktop (please complete the following information):

OS: Windows
Browser Chrome
Version 122.0.6261.95 (Official Build) (64-bit)

Start by tracing the backend route or entry point used by the vendors page's “Add restaurants” form, then reproduce the save action in Chrome and inspect the resulting error or response. The issue does not name a file, route, or test, so first identify where restaurant registration is handled. Done means the restaurant data is persisted and the form shows a success prompt.

Written by the indexing model from the issue text.