Hello,
As detailed on the addChart API documentation page (https://www.phpdocx.com/api-documentation/word-content/add-chart-Word-document-with-PHP), the current stable version of phpdocx allows setting custom font styles in the following chart contents:
- general chart properties, title => all licenses
- horizontalAxis, legend area, verticalAxis => Theme options only available in Premium licenses
The current stable version of phpdocx does not include an option to customize the font styles of data labels. To accomplish this task, a new option will be included in the next stable release.
Regards.