You’re correct. That is not a standard redirect URL. You could easily build some glue code to to look like an OpenID Connect compliant SP and then handle the redirect yourself. I am not super familiar with some of the OpenID Connect server options, but something like Hydra may be useful here. Perhaps some others from the community here can help with off the shelf options if you don’t want to code it yourself.
But coding it yourself may be the easiest, if you coded it in Node or something like that, it would be super simple, you’d have FusionAuth redirect to your node app and then you’d redirect to the video platform.
This is generally done by using the domain configuration. For example, all users with an email address domain of acme.com can be configured to use a particular SAML or OpenID Connect configuration.
As soon as you configure one IdP with a domain, the login panel will collect the email address first to understand if we need to ask for a password or forward them along to a federated identity provider.