While working in the editor, you can supplement the lesson with additional files (resources), e.g. images, audio, video, etc. This can be done in two ways – by uploading a file from your local computer or by entering the URL of the file available on the Internet.
If you choose the first option, the resource will be saved on the mAuthor server. In case of an export, the resource will be attached to the lesson's SCORM package. The export will work well even if you use an absolute reference to the asset on the mAuthor server (i.e. using it as an online resource with the address like this: https://www.mauthor.com/file/serve/2492516).
If you want to add to a lesson a resource from an external server...
1) Make sure you have the right to do so (check the resource's license).
2) Make sure that the resource is publicly available on the Internet (e.g. it is not required to log on to the server where the resource is stored or the resource does not come from the internal corporate network). A private mode in a browser and proxy servers can help you with this.
3) Make sure that the resource will remain at the URL as long as the lesson is available. Be aware of hosting "fly-by-night" companies and sites that may prohibit hot-linking of their materials. A big risk is also not renewing a domain or hosting service by the resource's owner.
4) Make sure that the lesson will not be used offline. Resources linked from external servers are not included in the offline lesson's package. Therefore, lessons with these resources will only work online. This may be a problem in the internal school's network or on a student's mobile device.
5) Make sure that all resources (for example custom fonts) which are imported in the presentation CSS styles are done so with scheme-less relative URIs (//) and they're available both via HTTP and HTTPS.