1. Open our Apple phone, and click the settings icon to enter the Apple phone settings page.

2. On the settings page of Apple's mobile phone, click General to enter the general settings page.

3. Then on the general settings page of the mobile phone, click the auxiliary function to enter.

4. On the accessibility page, we can choose bold text to change the font of our Apple phone to bold, or click on a larger font to enter.

5. Then change the size of the font style through the following settings.

6. Pull to the bottom of the accessibility page, and we can also click on the caption and closed caption settings.

7. Select a style after input, and select New Style on the Style page.

8. Then click on the font, set the required font and save it.