Is there any configuration to serve Grafana version 5.1.3 via ifram?

I’m using an old version of Grafana (5.1.3) that I can bring up Grafana using <iframe> in a JS code properly. But now, I’m using React JS with a separate Nginx. In this situation, I cannot see Grafana via <iframe>. So I looked for the reason and I saw there is a variable in grafana.ini named allow_embedded. However, it seems that this variable doesn’t exist in this version.

My question is, apart from updating the Grafana version, how can I deal with this issue? For example, using a special Nginx configuration. And in what version of Grafana this ability was released?