Docker container can't find pdf from directory

Question

I have a next.js app that contains a pdf file in pdfs/example.pdf. However when I run my docker image I get a 404 error in the pdf viewer on the webpage.

below is my dockerfile:

# Get NPM packages
FROM node:14-alpine AS dependencies
RUN apk add --no-cache libc6-compat
WORKDIR /app
COPY package.json package-lock.json ./
RUN npm ci --only=production

# Rebuild the source code only when needed
FROM node:14-alpine AS builder
WORKDIR /app
COPY . .
COPY ./pdfs/ ./pdfs/
COPY --from=dependencies /app/node_modules ./node_modules
RUN npm run build

# Production image, copy all the files and run next
FROM node:14-alpine AS runner
WORKDIR /app

ENV NODE_ENV production

RUN addgroup -g 1001 -S nodejs
RUN adduser -S nextjs -u 1001

COPY --from=builder --chown=nextjs:nodejs /app/.next ./.next
COPY --from=builder /app/node_modules ./node_modules
COPY --from=builder /app/package.json ./package.json
COPY --from=builder /app/pdfs/ ./pdfs/

USER nextjs
EXPOSE 3000

CMD ["npm","run","start"]