1. Open the WeChat application and log in the account.

2. Click the "I" icon in the lower right corner of the bottom navigation bar to enter the "I" interface.

3. Find and click the Settings button in the upper right corner of the "Me" interface.

4. After entering the settings page, slide down to the option name "General" and click to enter the related settings menu.

5. Look for an option named "Multilingual" or something similar in the General Settings menu, and click to enter the submenu.

6. Look for the switch or check box named "Bold" in the multilingual submenu.

7. After completing the above steps, return to the main interface to confirm whether the changes take effect. You can try sending a message to yourself to test whether bold is used when entering text.