Problem connecting to database while using Flexmonster data server

Good Evening.
I am currently trying to set up the Flexmonster data server to try to retrieve data for a Pivot table using for now a mock table we have in an SQL database.
When I try to execute the file "flexmonster-data-server.exe", the error that you can see in the attached image appears so I cannot get to connect to it.
This is the slice of code I use in the configuration file:

 
    "DataSources": [
        {
            "Type": "database",
            "DatabaseType": "mysql",
            "ConnectionString": "Server=ec2-54-246-87-132.eu-west-1.compute.amazonaws.com;Port=5432;Uid=ipqwiwsncewoaj;Pwd=7384352041f1a0fd6e980a68f07bf42fa864f12619384e1c6466fa4b3330d641;Database=df5qo1ifjaaf8f",
            "Indexes": {
                "index_database": {
                    "Query": "SELECT * FROM allianz.DummyTable"
                }
            }
        }
    ],

 
Thanks for everything.
Javier Sanz.