That seems legit to me.
DRM content is usually encrypted and only decrypted through some proprietary plugins, so you have to agree to use these plugins if you want to watch these videos.
This is the same mechanism that Netflix and Disney+ use and it helps them by not letting you download movies to your computer.
While I use LibreNMS as it uses SNMP for monitoring (which is pretty much available everywhere), I don’t believe it has http alerts, but I know for a fact that it can send Telegram messages.