Trying to move files in Powershell gives Error 404

Good day all, I am new to dropbox development and am trying to do something simple, post a file to one directory (done) and then have another script move that file to another directory after downloading it.  I am just working on the move piece and keep getting a 404 error and nothing seems to work.  And the file.contents.write properties have been set as well.  If I simply do a file upload to the second folder, that works, but not a move.

$authorization = "Bearer $AccessToken"

# move file to other folder

$arg = '{"allow_ownership_transfer":false,"allow_shared_folder":false,"autorename":false,"from_path":"/incoming","to_path":"/completed"}"'

$headers = New-Object "System.Collections.Generic.Dictionary[[String],[String]]"
$headers.Add("Authorization", $authorization)
$headers.Add("Content-Type", 'application/json')
$headers.Add("Dropbox-API-Arg", $arg)

Invoke-RestMethod `
-Uri https://api.dropboxapi.com/2/files/move_v2 `
-Headers $headers