TypeError: firebase.firestore is not a function
    at firebase.auth.signInWithCustomToken.then (/user_code/index.js:28:19)
    at e.g (/user_code/node_modules/firebase/node_modules/@firebase/auth/dist/auth.js:23:101)
    at Yb (/user_code/node_modules/firebase/node_modules/@firebase/auth/dist/auth.js:26:195)
    at Ub (/user_code/node_modules/firebase/node_modules/@firebase/auth/dist/auth.js:26:85)
    at z.h.Mb (/user_code/node_modules/firebase/node_modules/@firebase/auth/dist/auth.js:25:303)
    at Cb (/user_code/node_modules/firebase/node_modules/@firebase/auth/dist/auth.js:19:42)
    at process._tickDomainCallback (internal/process/next_tick.js:135:7)