Is it possible to turn off automatic alt text generation?

Yes, definitely! Just go to the plugin Settings page, and UN-check the box for:

When new images are added => [ ] Automatically generate alt text with AltText.ai

This will turn off the auto-generation, but you can manually process images either from your image library, bulk generate page, or using our refresh alt text features.

Feel free to check out our documentation here: https://alttext.ai/docs/integrations/wordpress/

Thanks!