If unauthenticated users should use your post request, there are several ways:

1. Add RECAPTCHA. Just use this package react-google-recaptcha-v3 in your form, and verify user on submit.
2. Use FingerprintJS or alternative one to identify abusive users and store the fingerprint in your database to track requests.
3. And read this issue as well: How effective is the honeypot technique against spam?