Can't Install Shopify App Deployed on AWS Fargate – Connection Denied

I have a Shopify app that I’m trying to deploy through AWS Fargate. I’ve set up the app and it’s running on Fargate, however, when I try to install it from the Shopify partner dashboard, I get the message that the page "myapp.mydomain.com" has denied the connection.

I’ve checked the allowed redirection URLs in the partner dashboard, and I’ve updated them with the correct Fargate endpoint. I’ve also tested that the server is running correctly by providing another HTTP endpoint on port 80, and it works just fine.

What could be causing the issue? Are there any additional steps I need to take when deploying a Shopify app on Fargate? Any help would be greatly appreciated!

This is my dockerfile

FROM amd64/node:18-alpine

ARG SHOPIFY_API_KEY
ARG SHOPIFY_API_SECRET
ARG VERSION
ENV SHOPIFY_API_KEY=${SHOPIFY_API_KEY}
ENV SHOPIFY_API_SECRET=${SHOPIFY_API_SECRET}
ENV SCOPES="write_products"
ENV PORT=8081
ENV HOST="https://myapp.mydomain.com"
ENV SHOP="mystore-dev-1.myshopify.com"


EXPOSE 8081
EXPOSE 80
WORKDIR /app
COPY web .
RUN npm install
RUN cd frontend && npm install && npm run build
CMD ["npm", "run", "serve"]

Thanks in advance!

I’ve tried to deploy it several times in different clusters but it just doesn’t works.

I’m expecting, that the app can just be normally installed in my dev store in the same way as the currently working local deployment with a ngrok tunnel.