VERCEL_URL - dynamic Convex env

Hey there! I need to figure out the best way to handle VERCEL_URL. We are constructing clerk invitations in our Convex functions and need to generate a redirect url for the invitations. We want this to work for our preview deploys and prod. Prod is easy technically as it's a static domain and we could just explicitly set VERCEL_URL in the dashboard, but this doesn't work for previews.

So what is the best/easiest option for setting this in Convex during Vercel deployments? Thank you!