having the same problem here, would love to see a solution!
$ EXPO_DEBUG=true expo push:web:generate --vapid-subject "mailto:myemail@mydomain.com"
┌──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ │
│ There is a new version of expo-cli available (3.13.6). │
│ You are currently using expo-cli 3.11.7 │
│ Install expo-cli globally using the package manager of your choice; for example: `npm install -g expo-cli` to get the latest version │
│ │
└──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
Reading project configuration...
Logging in...
Generating and setting VAPID keys on Expo's servers...
Request failed with status code 404
Error: Request failed with status code 404
at createError (/usr/local/lib/node_modules/expo-cli/node_modules/axios/lib/core/createError.js:16:15)
at settle (/usr/local/lib/node_modules/expo-cli/node_modules/axios/lib/core/settle.js:17:12)
at IncomingMessage.handleStreamEnd (/usr/local/lib/node_modules/expo-cli/node_modules/axios/lib/adapters/http.js:237:11)
at IncomingMessage.emit (events.js:215:7)
at endReadableNT (_stream_readable.js:1184:12)
at processTicksAndRejections (internal/process/task_queues.js:80:21)