Either require kaleidpixel/ImageOptimizer through composer or download the repo and include the old way.
- Image Optimizer (This library): MIT License https://github.com/kaleidpixel/image-optimizer/blob/master/LICENSE
- webp: BSD License
https://www.webmproject.org/license/software/ - gifsicle: GPL version 2 License
https://github.com/kohler/gifsicle/blob/master/COPYING - jpegtran: MIT License
https://github.com/imagemin/jpegtran-bin/blob/master/license - pngquant: GPL version 3 License
https://github.com/kornelski/pngquant/blob/master/COPYRIGHT - oxipng: MIT License
https://github.com/shssoichiro/oxipng/blob/master/LICENSE - svg-sanitizer: GPL version 2 License
https://github.com/darylldoyle/svg-sanitizer/blob/master/LICENSE - cavif: BSD 3-Clause License
https://github.com/kornelski/cavif-rs/blob/main/LICENSE