Is Please submit the report to Johanna or myself correct grammar?

The grammar is technically correct, but it's a bit awkward. It's better to avoid using "myself" in this context. Here are some better options:

* Please submit the report to Johanna or me. (This is the most grammatically sound and natural option.)

* Please submit the report to Johanna or to me. (This is also grammatically correct, but a bit more formal.)

The reason "myself" isn't ideal is that it's usually used for emphasis or to avoid ambiguity, neither of which are present in this sentence. "Me" is the correct object pronoun in this case.