Login to mlab/mongodb first:
https://account.mongodb.com/account/login.
1. Then click on "Database" on the left, then
2. right click "Connect",
3. then on "Connect with mongodb shell",
and then
4. copy this between:
"mongodb+srv://" und "/myFirstDabase"
That like e.g.
cluster0.7fhhjbf.mongodb.net is then the
Mlab DB Host.
You should know the database name, username and password. Otherwise you can also look for them from the Heroku "vars".
Dann die Checkbox bei "Mlab ATLAS" aktivieren, die Ziel-Instance auswählen und speichern.
Then the checkbox at "Mlab ATLAS" activate, select the target instance and save.
If it doesn't work, please get in touch with us using the
contact form. We will then help you with that.