If it was developed in 2013 it was likely hand coded (Brightscript)? In order to 'update it' I don't know that there's much of a way other than recoding it altogether. Maybe if it wasn't that long ago you could have minor tweaks here & there, but things are likely outdated, non-copatible etc and it'd be better/faster/cheaper to start from scratch. Think of it like an outdated website from years ago.
There's a separate section, for the 'Developers' area. Otherwise, you could consider switching to this section, Direct Publisher. It's kinda like Wordpress or a Shopify site, a little more pre-built and easier to build. Still requires a bit of coding knowledge & ability, some of us on the forum are willing to assist to an extent. Start to finish shouldn't take more than maybe 2 weeks, doing it solo and kinda part time, although, depends how many videos you have, it's tedious but repetition.
If you had your site built using a 3rd party software, you'd likely need to reach out to them to see about updating versus rebuild. Generally speaking discussion and troubleshooting/Tech Support really isn't to be discussed on this site.