Failing to deploy on Vercel and Heroku

When i try to deploy to vercel it says error! Command "npm run build" exited with 1 vercel
when i try to deploy to heroku it says ! [remote rejected] master -> master (pre-receive hook declined)

When i deploy to Github pages it then shows a frontity page. I have tried everything in the answers and frankly I’ve had enough. Not so good for a first try with frontity.