Still failed to run doppler in fly.io

I followed this guide: Fly.io

app : web app
server: fly.io

this my dockerfile :

FROM base

RUN mkdir /app
WORKDIR /app

ENV NODE_ENV=production

# Install Doppler
RUN (curl -Ls --tlsv1.2 --proto "=https" --retry 3 https://cli.doppler.com/install.sh || wget -t 3 -qO- https://cli.doppler.com/install.sh) | sh

COPY --from=production-deps /app/node_modules /app/node_modules

COPY --from=build /app/build /app/build
COPY --from=build /app/public /app/public
ADD . .

CMD ["doppler", "run", "--", "yarn", "run", "start"]

I get this error:

ode:internal/modules/cjs/loader:959
2022-10-11T10:12:54Z   [info]  throw err;
2022-10-11T10:12:54Z   [info]  ^
2022-10-11T10:12:54Z   [info]Error: Cannot find module '/app/doppler'
2022-10-11T10:12:54Z   [info]    at Function.Module._resolveFilename (node:internal/modules/cjs/loader:956:15)
2022-10-11T10:12:54Z   [info]    at Function.Module._load (node:internal/modules/cjs/loader:804:27)
2022-10-11T10:12:54Z   [info]    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12)
2022-10-11T10:12:54Z   [info]    at node:internal/main/run_main_module:17:47 {
2022-10-11T10:12:54Z   [info]  code: 'MODULE_NOT_FOUND',
2022-10-11T10:12:54Z   [info]  requireStack: []