Looking for accounting software for small businesses

I am self-employed and run an accounting service. I am looking for a streamlined accounting software solution for my office that can handle a maximum of 30 transactions per month.

It should be on-premises, but if the terms and costs of the solution are acceptable, a cloud-based version would also be an option.

The software should meet the following requirements:

• Debit and credit
• Journal entry line - manual entry of transactions, income/expense entries (based on DATEV)
• Ability to print expense and revenue accounts
• Suitable for small businesses
• Streamlined solution - cost-effective
• No accruals, no invoices, no open items
• No interfaces
• On-premises installation preferred

One software workstation is planned. The system will run on MS Windows 11.