We know that video details like video_cta, video_description could be set by POST accounts/:account_id/tweet API, but we can’t find the relational setting for POST accounts/:account_id/scheduled_tweets.
video_cta
video_description
POST accounts/:account_id/tweet
POST accounts/:account_id/scheduled_tweets
Thanks for the question, @wenping.wang. You’re correct that there currently isn’t a way to do this.