Added SMTP settings to my config.production.json file for the Ghost install on my droplet and now I am seeing 502 Bad Gateway?

Following the guidance of the config docs provided online by Ghost, and having established a Mailgun account, I opened config.production.json using nano via the console provided by DigitalOcean, added the necessary settings to establish SMTP, saved the update by hitting ^X and then enter. I ran GHOST RESTART, and all seemed well, but when I go to the URL, now there is a 502. Any advice is welcome.

The updated JSON is below with the password removed. Thank you.

{

“url”: “https://helenafitzgerald.com”,

“server”: {

"port": 2369,

"host": "127.0.0.1"

},

“database”: {

"client": "mysql",

"connection": {

  "host": "127.0.0.1",

  "user": "ghost-991",

  "password": ".2I[UTS9dIw[Du82NmeP",

  "port": 3306,

  "database": "ghost_production"

}

},

“mail”: {

"transport": "SMTP"

"options": {

  "service": "Mailgun",

  "auth": {

    "user": "postmaster@mail.helenafitzgerald.com",

    "pass": "[removed for posting]"

  }

}

},

“logging”: {

"transports": [

  "file",

  "stdout"

]

},

“process”: “systemd”,

“paths”: {

"contentPath": "/var/www/ghost/content"

}

}