Error in Production on OAUTH callback

[harperaa]

Hi, starter works well in dev, but when moving to production, ensuring correct callback in Github, and correct ID and Secret from Github in environment variables on Vercel, I keep getting an error when trying to authenticate.

Deployed site for confirmation here: https://code4rena-browser.vercel.app/

I have standard code base, fresh from git clone, no changes besides environment variables on Vercel.

I get this in the URL after trying to authenticate and after Github authorization: api/auth/signin?error=Callback

Settings in Vercel Environment Variables:
NEXTAUTH_URL=https://code4rena-browser.vercel.app
GITHUB_CLIENT_ID
GITHUB_CLIENT_SECRET
NEXTAUTH_SECRET <set correctly using openssl rand -base64 32>

Settings on Github

I have scoured the internet, have seen some talking about this situation with nextauth, but I don't see an explanation or fix...

[harperaa]

Update, I found the problem, it was the mongodb uri, the one generated by the script was in this format (password masked):
mongodb+srv://vercel-admin-user:***************@cluster0.nvhefxh.mongodb.net/admin

I had to change it to this format (obtained from mongodb atlas dashboard-connect settings)
mongodb+srv://harperaa:*************@cluster0.mgwkzjj.mongodb.net/?retryWrites=true&w=majority

That solved it, so something is wrong with the vercel-mongo script. I also recommend you guys add some notes in the .env.local.example file, that lets users know to add the GITHUB_CLIENT_ID and GITHUB_CLIENT_SECRET and the NEXTAUTH_URL variables to the environment settings on vercel, after the initial build... or better yet, collect them in the build script, as it appears to do with NEXTAUTH_SECRET. That is not intuitive, for new users like me...

Anyway, it works now, thanks for starter... hope you can fix above so others can enjoy the package.