Unfortunately, it is unsupported to translate report to multiple languages dynamically in Power BI currently. I'd like to suggest you vote on the idea and add your comments there to improve Power BI for making this feature coming sooner.
Or you can use python visual to show the chart. Create a parameter for python visual to change the header language.
Community Support Team _ chenwu zhu
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.