1. In your country or region, visit the official website of HSBC or use related mobile applications.
2. Log in to your personal bank account or commercial bank account according to your account type and needs.
3. Navigate to the online banking service page or a specific page related to financial management.
4. Submit the relevant application form online or print and fill in the application form.
5. Submit the application form and wait for the bank to review and process your application.
6. If your application is approved, HSBC will open a business online financial account and provide the euro trading function you need.
Please note that the specific opening steps may vary from country to country. It is suggested that you learn more about online banking and euro trading in official website, or contact the customer service department of HSBC directly for consultation.