Creating Connection of an existing Mongo DB Database in an existing Docker Container

I want to create a connection from an existing Mongo DB collection to an existing Docker container. Can anybody see it out.

I tried out several syntaxes and approaches but It always give me error.
Thanks in advance!

player-cloud_1  | error  { MongoError: failed to connect to server [cluster0.bgso9.mongodb.net:27017] on first connect [MongoError: getaddrinfo ENOTFOUND cluster0.bgso9.mongodb.net cluster0.bgso9.mongodb.net:27017]
player-cloud_1  |     at Pool.<anonymous> (/app/node_modules/mongodb-core/lib/topologies/server.js:336:35)
player-cloud_1  |     at Pool.emit (events.js:182:13)
player-cloud_1  |     at Pool.EventEmitter.emit (domain.js:442:20)
player-cloud_1  |     at Connection.<anonymous> (/app/node_modules/mongodb-core/lib/connection/pool.js:280:12)
player-cloud_1  |     at Object.onceWrapper (events.js:273:13)
player-cloud_1  |     at Connection.emit (events.js:182:13)
player-cloud_1  |     at Connection.EventEmitter.emit (domain.js:442:20)
player-cloud_1  |     at Socket.<anonymous> (/app/node_modules/mongodb-core/lib/connection/connection.js:189:49)
player-cloud_1  |     at Object.onceWrapper (events.js:273:13)
player-cloud_1  |     at Socket.emit (events.js:182:13)
player-cloud_1  |     at Socket.EventEmitter.emit (domain.js:442:20)
player-cloud_1  |     at emitErrorNT (internal/streams/destroy.js:82:8)
player-cloud_1  |     at emitErrorAndCloseNT (internal/streams/destroy.js:50:3)
player-cloud_1  |     at process._tickCallback (internal/process/next_tick.js:63:19)
player-cloud_1  |   name: 'MongoError',
player-cloud_1  |   message:
player-cloud_1  |    'failed to connect to server [cluster0.bgso9.mongodb.net:27017] on first connect [MongoError: getaddrinfo ENOTFOUND cluster0.bgso9.mongodb.net cluster0.bgso9.mongodb.net:27017]' }
player-cloud_1  | error connecting to the database