You must initiate the ACH Pull transaction by the account receiving the deposit, not by Nomad.
The other institution will link both accounts through micro-deposits.
You must confirm the amount of these deposits with the bank to prove that you can access both accounts.
After this verification, you can initiate ACH Debit from your account in the other institution
Nomad does not charge any fees for this transaction.
To see your account details, go to "Profile" > "Banking details" > "Banking account."