Setting up remote file access

I have a friend who lives on the other side of the world to me and I would like to give them access to a share on my device since I have an abundance of space. The issue is, I don’t know how to go about setting it up. I was thinking a web file viewer or perhaps FTP access. I tried following some steps found on this forum about setting FTP up but had no luck when I tried accessing it through Filezilla with my public IP.
It may be a problem but I cannot forward port 21 on my router (I chose 211 and entered that during setup).

I would prefer setting up a web file viewer since my friend has no experience with FTP. Can someone point me to a guide or share some steps to bring me closer to a solution.

Thanks.

Hi there, you can use mycloud.com, which is a browser-based file and content remote access utility for My Cloud devices. For more information, visit the link below.

https://support.wdc.com/knowledgebase/answer.aspx?ID=19526