Cannot build frontend

[asheghi]

steps to reproduce:

cd frontend
yarn
yarn dev

ERROR in Cannot find module 'babel-core'

yarn add babel-core
yarn dev


ERROR in ./src/index.jsx
Module build failed: SyntaxError: Unexpected token (26:6)

  24 |     var pagecontainer=[];
  25 |     pagecontainer.push(
> 26 |       <div>
     |       ^
  27 |         <Attendance />
  28 |       </div>
  29 |     )

node version 12.22
yarn version 1.22

it seems to be a misconfiguration in webpack or babel config files