location /sse {
proxy_pass https://example.com/sse;

proxy_buffering off;

proxy_set_header Cache-Control 'no-cache';
proxy_set_header Connection 'keep-alive';

proxy_set_header Host $http_host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
}
}