Required fields for FM 'MRM_INVOICE_PARK'?

Hello Experts-

Have any of you used the FM 'MRM_INVOICE_PARK' for parking a non-PO invoice?

I want to test this FM but don't know which fields are required. Can one of you please guide me as to which fields need to be filled out in order to even test this FM?

Thank you,

- Vik.