Looks like a copy & paste error.
Change:
"ConnectionStrings": {
"MovieContext": "Server=(localdb)\\mssqllocaldb;Database=Movies;Trusted_Connection=True;MultipleActiveResultSets=true\""
}
to:
"ConnectionStrings": {
"MovieContext": "Server=(localdb)\\mssqllocaldb;Database=Movies;Trusted_Connection=True;MultipleActiveResultSets=true"
}
I have removed the
\"
at the end.