Importing transactions (automatically) into Firefly III is one of the most asked features of Firefly III. Everybody wants Firefly III to automatically connect to their bank and synchronize all transactions.
In order to import transactions into Firefly III, you'll have to install and run separate tools. These tools can do the sync for you.
It's not as easy as YNAB or Mint, and it's never going to reach that level of sophistication.
Your bank may not be supported, despite our best efforts.
You might not be able to easily automate the import/sync process.
A universal tool to import transactions into your Firefly III installation is the CSV importer. If that fails, check out the Spectre importer. The Spectre API is provided by a fintech company called Salt Edge. They offer a trial of their Spectre API which you can use to connect to your bank.
If you want to import transactions using FinTS, from Revolut or Plaid, use the tools made by Firefly III users listed below.
The Spectre API is a paid product. After a short testing period, you must pay for the use of the Spectre API.
A separate tool, built by GitHub user @bnw, can import FinTS.
A separate tool, built by GitHub user @Ludo444, can import Revolut.
If none of these import methods support your bank or financial org, please check out the API.