Hiya,
The traditional spider will not be able to handle a React SPA very well, so the AJAX Spider is the way to go.
Try running it from the ZAP desktop using a non headless browser.
You should see the browsers being launched and ZAP attempting to navigate around the target site.
It may be obvious whats going wrong - for example ZAP not getting past a login page.
If its not obvious whats going wrong then let us know what you observe.
Cheers,
Simon