I don't think this will work, your Kibana is configured to listen on HTTPS, but your Nginx is using HTTP and Kibana won't accept it.
You will need to disable HTTPS in Kibana, which is not recommended, or use a redirect directive in NGINX to redirect the traffic from 8080 to 5601, you will need to check NGINX on how to do that.
I was need access kibana on port 443 (https). I've resolved this problem set up kibana.yml with server port 443 and public url https://myip:443.
Now I access kibana just https://myip.
To resolved problem about low port, I've used these commands:
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