It is well known that WordPress does not allow the upload of the SVG files and the main reason is that they are unsecure. This is because the SVG is not an image format but a document format (consider that SVG files allow JavaScript to be embedded). For that reason, we did not add the function to allow the SVGs upload in Fildisi.
However, we support these for the users that will upload SVC files in their installations in various elements (Icon, Icon Box, Counter). How can you upload a SVG file? All you need is to install and activate a plugin for this (eg https://wordpress.org/plugins/safe-svg/).
Last but not least, a nice place that you can download for free or purchase and use SVG files is here: https://www.streamlineicons.com/.
Themes must not enable SVG uploads as it raises security concerns due to the possibility of attackers executing malicious code through SVG’s XML. For more information on SVG uploads, refer to SVG uploads in WordPress article.