The submit token is NOT YOUR LOGIN PASSWORD.

If you are trying to submit your solution using sbt, like this.

> sbt submit user@some.address.com SoMeToKeN
...
...
[error] Invalid input to `submit`. The required syntax for `submit` is:
[error] submit <email-address> <submit-token>
[error]
[error] The submit token is NOT YOUR LOGIN PASSWORD.
[error] It can be obtained from the assignment page:
[error] https://www.coursera.org/learn/scala-spark-big-data/programming/CfQX2
[error] or (for premium learners):
[error] https://www.coursera.org/learn/scala-spark-big-data/programming/QcWcs
[error]
[error]
...
...

you might find this one a solution for you. Start sbt, and run submit from there.

> sbt
> submit user@some.address.com SoMeToKeN
[info] Attempting to submit "wikipedia" assignment in "scala-spark-big-data" course
[info] Using:
[info] - email: user@some.address.com
[info] - submit token: SoMeToKeN
[info] Connecting to Coursera...
[info] Successfully connected to Coursera. (Status 201)
[info]
[info] Assignment submitted successfully!
[info]
[info] You can see how you scored by going to:
[info] https://www.coursera.org/learn/scala-spark-big-data/programming/CfQX2/
[info] or (for premium learners):
[info] https://www.coursera.org/learn/scala-spark-big-data/programming/QcWcs
[info]
[info] and clicking on "My Submission".