Certificate images
From MoodleDocs

Certificate images are managed centrally and act as a simple repository for assets that can be used in the Image element in Certificate templates, for instance, your company logo or the signatures of certificate signees.
Certificate images are managed in Site administration > Certificates > Certificate images.
Supported image file types are AI, BMP, GDRAW, GIF, ICO, JPE, JPEG, JPG, PCT, PIC, PICT, PNG, SVG, SVGZ, TIF, and TIFF.
The permission Manage certificate images (tool/certificate:image) has to be granted to access this feature.