If you have your bank accounts and/or credit card linked to Hurdlr, then you should be categorizing your transactions from the Expenses section and Income section of Hurdlr. Those sections allow you to categorize transactions to various accounts (e.g. categorizing an Expense as an Asset, which will update your General Ledger and Balance Sheet accordingly), leading to a cleaner “book”, and an easy way to see which bank transactions link to which accounts.
With that being said, there are times when you might need to make a manual journal entry to account for something that is not an Expense or Income, and that did not originate from the bank. If you are sure that you need to do that, you can do so by entering a new manual journal entry, go to the General Ledger in the Accounting section of Hurdlr, then click the "+Add Entry" button in the top right corner. From there, you can enter the entry details and click "Save" to save it. Please consult your bookkeeper before making manual journal entries.