Several budgeting apps use open banking api to connect to bank accounts and update the entries (money in or money out). Once it's synced you can assign the appropriate category. Usually, the budgeting app "learns" over time and it does the categorisation automatically based on the payee and your budget.

The system isn't perfect but, in my experience, it works 90% of the time. The remaining 10% requires manual categorisation. I suppose it also depends on how simple or complex your budget and your spending are.