The payment method is as follows:

1. Download and install the Shanghai Tax App.

2. Open the app and enter the homepage.

3. Find "Social Security Payment" or a similar option on the homepage or menu.

4. Click to enter the social security payment page.

5. Fill in the personal identity information according to the prompts and ensure it is accurate.

6. After entering the payment page, follow the guidelines to select social security payment for flexible employment personnel and fill in the relevant information.

7. Complete the payment process according to the guidelines of the app.