The financial transactions will be imported automatically (for Job Queue settings check Job Queue Entry). The job queue imports the bank transactions, creates payment reconciliation lines (W1) or puts all the transactions in the Bank/Giro journal (NL).
If you use the local functionality from Microsoft Dynamics 365 Business Central, without the Direct Banking extension, you have to import the electronic bank statement for all your financial interactions manually. You have to regularly reconcile your bank, receivables, and payable accounts by applying payments recorded in the bank to their related open (unpaid) invoices and credit memos or other open entries in Business Central.

Adjusting Bank Account Card (Customer and/or Vendor)

The Direct Banking extension automatically imports the transactions when the job queue is set up. From the CBG Statement Lines you can add the bank account to a customer or a vendor if the a payment is done from a new customer/ vendor bank account. Select the right customer, select the dots and choose the function Create Bank Account. Business Central gives you the warning if you want to add the account to the specific Customer or Vendor, you can edit the Customer/Vendor Bank Account Card if you want.