I work in web development, and it's standard practice at my current job to have videos captioned before they go up on a website, but I realized recently that text in a video that doesn't have an audio equivalent is very much not accessible!

I did a ton of googling but I couldn't find a great answer to this, specifically- what is the best way to provide an equivalent to text edited into a video for visually impaired users? Are you able to access the closed captions on a site like Vimeo using screen readers? Would a simple transcript of the information below the video work? Is there a standard for this you see a lot, do you have a preference for how this is done?

For more context, the video in question that was submitted to us to be put on the site is just graphics with only background music as the audio. There's a flowchart describing a topic and two cartoon people having a discussion using speech bubbles. It looks like it was created using a site called "Vyond", and their page on accessibility basically tells users to make their own transcripts for these videos. I am leaning towards having a transcript made, but the service we use (Rev) only mentions transcripts of audio, so I'm not even sure if they create transcripts for on-screen information only. I find it crazy that I can't find a resource for what is considered standard practice for this! Everyday I seem to rediscover just how far we have to go in digital accessibility standards lol

Thank you in advance for any insight you can give me!