If you like this workflow, there is an improved version that also includes the possibility to upscale a video if you want, you can find it here, if you only need interpolation you can of course still use this one.

https://civarchive.com/models/547371/jaynlinterup

But of course I advice to download the version above so you have all in one!

Is your video too short or too fast, with this workflow you can make it longer/slower by interpolation in seconds.