You can link your bank and credit accounts via the menu item
Add-ons > BudgetSheet > Link New Bank Account
This will popup a modal dialog for you to connect your bank account(s).
Bank accounts are connected with and managed by Plaid. BudgetSheet does not handle or store any sensitive banking credentials.
After at least one bank account is linked, you can import bank transactions.
Google Sheets + Bank Transactions. Full control to budget your own way with your own data in your own spreadsheet.