The HypoVereinsbank only offers collective direct debits via HBCI / FinTS, no single direct debits.
Currently Outbank does not support collective direct debits, but we will add this feature with a future update.
HVB: why can't i submit a direct debit with my HypoVereinsbank account? - iOS-Version / Banks and Providers - Outbank Helpdesk
hvb, hypovereinsbank, laschrift