Reverse Proxy Multiple Endpoint Question

Hi Everyone,

Is the following possible? :

I have 3 endpoints, 1 in UK South, 1 in West Europe, 1 in North Europe :

uks-ngx001.test.com
weu-ngx001.test.com
neu-ngx001.test.com

 # Reverse proxy for other requests     
location /
{  proxy_pass http://uks-backend;         
proxy_set_header api-key "xxxxxxx";

}

I've deployed 3 VMs hosting NGINX with a similar config to the above as it sits in front of an endpoint in the related region.

Is it possible to have health check of some sort that if a 200 response is not received for the proxied request that the request can be forward to one of the other 2 endpoints automatically with their respective api-keys : weu-ngx001.test.com = aaaaaa neu-ngx001.test.com = bbbbbb ?