Sharing gofile links of large video files

Hi, we have video files over 3GB that we need sharing to external users, we use the gofile feature to send them a link to download the file.

The problem is they are in another country and takes too long to download from their side and also the download gets interrupted. We have good fibre internet in our office 1GBPs/500Mbps yet they still have problems downloading files.

Is there another way to share these files or optimally setup the synology connection for upload and download speeds?