Payment Voucher

hello

I need clarification on Bank Account  Payment document number  creation:-.

Assigned Payment document category >   Manage Bank Accounts: Account Controls  >   Account Access  >   Update Bank Account: Organization Access  >  Payment Document Categories by Payment Method  no

Then in payment Voucher Voucher number not getting generated.

Assigned  Document category   >  Manage Bank Accounts: Account Information  >   Bank Accounts  >   Payment Documents  >  Payment Document Category

Then Voucher number is not generated.

Why so pl Clarify.

Thanks

Gobind