Anti-fraud tests fail immediately due to 503 from heimdall

I input values for the tests. When I select the “Run Tests” button, a message is never sent to the specified url. Before that happens, an OPTION and then a POST both fail with a 503.

CORS 503
Service Unavailable: Back-end server is at capacity

OPTIONS /api/antifraud-provider/execute-test HTTP/1.1
Host: heimdall.vtexpayments.com.br
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:109.0) Gecko/20100101 Firefox/111.0
Accept: /
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br
Access-Control-Request-Method: POST
Access-Control-Request-Headers: content-type
Referer: https://{snipped}.myvtex.com/
Origin: https://{snipped}.myvtex.com
Connection: keep-alive
Sec-Fetch-Dest: empty
Sec-Fetch-Mode: cors
Sec-Fetch-Site: cross-site

POST /api/antifraud-provider/execute-test undefined
Host: heimdall.vtexpayments.com.br
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:109.0) Gecko/20100101 Firefox/111.0
Accept: application/json
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br
Referer: https://{snipped}.myvtex.com/
Content-Type: application/json
Content-Length: 281
Origin: https://{snipped}.myvtex.com
Connection: keep-alive
Sec-Fetch-Dest: empty
Sec-Fetch-Mode: cors
Sec-Fetch-Site: cross-site