Mup with atlas hosted cluster and oplog

Im trying to deploy app on DO using mup. Im trying to use mongo atlas hosted cluster.

here is related part of mup.js

    env: {
      MONGO_URL: 'mongodb+srv://<user>:<password>@xxxxx.mongodb.net/myDatabase',
      MONGO_OPLOG_URL: 'mongodb+srv://<user>:<password>@xxxxxx.mongodb.net/local',
    },

i do mup deploy and i see error that is hard to understand for me

[161.35.204.78] x Verifying Deployment: FAILED

	      ------------------------------------STDERR------------------------------------
	      go/node_modules/mongodb-core/lib/connection/pool.js:845:20
	    at /built_app/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/auth/scram.js:266:20
	    at /built_app/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/connection/pool.js:532:18
	    at _combinedTickCallback (internal/process/next_tick.js:131:7)
	    at process._tickDomainCallback (internal/process/next_tick.js:218:9)
	=> Starting meteor app on port:3000
	Note: you are using a pure-JavaScript implementation of bcrypt.
	While this implementation will work correctly, it is known to be
	approximately three times slower than the native implementation.
	In order to use the native implementation instead, run

	  meteor npm install --save bcrypt

	in the root directory of your application.
	/built_app/programs/server/node_modules/fibers/future.js:313
							throw(ex);
							^

	Error: authentication fail
	    at /built_app/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/topologies/replset.js:1456:15
	    at /built_app/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/connection/pool.js:869:7
	    at /built_app/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/connection/pool.js:845:20
	    at /built_app/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/auth/scram.js:266:20
	    at /built_app/programs/server/npm/node_modules/meteor/npm-mongo/node_modules/mongodb-core/lib/connection/pool.js:532:18
	    at _combinedTickCallback (internal/process/next_tick.js:131:7)
	    at process._tickDomainCallback (internal/process/next_tick.js:218:9)

It straight forward that authentication fails, but what authentication if user and password are correct add additionally if run mup deploy witout MONGO_OPLOG_URL deploy works.
Additional question is what happen, in such case? Meteor run without oplog?
Thx in advance.

Edit : i forgot to mention that connecting to 'mongodb+srv://<user>:<password>@xxxxxx.mongodb.net/local' with mongo shell works without any issues.