1. The first step is to click the "More" option on Alipay's homepage.

2. Step 2: On the "More" page, find the "medical and health" option under the classification of "convenient life".

3. Step 3 You can see "Self-test of Body Mass Index" in the upper part of the opened page, and click Enter.

4. Step 4: Enter the height and weight in the opened page as required, and click the confirm button below to get the body mass index value.