I have found this guide for webp (it is in Spanish, but can be easily translated):
It recommends to use this plugin:
This is our documentation to install plugins:
Please let us know if you find any issue installing the plugin.
Please note that Bitnami packages and configures already existing applications. However, we can only offer support and help on basic and most frequent application configurations. Always based on the default configuration or on our guides.
If the question is related to the usage of the plugin, probably someone with more experience and knowledge about that specific tool can help you better than we can. We suggest you to post your question on the official support forums of the application.
I hope it helps