error in import playbook

hi,
here is simple example:

wrapper play book

In a yaml file it is usual one of:

  1. Indentation does not line up
  2. tabs vs spaces (they look the same, but count as different indents)
  3. invisible characters (look like blanks or none, but are not understood by the program)

I don’t see anything, but the mail client could have changed characters.
yaml still confuses me.
Should “- always” be indented more?