Extending Docker image not running on AWS Fargate

I’m trying to run CubeJS on AWS Fargate, if I use the image cubejs/cube:v0.33.33 directly on in a JSON file on Fargate it runs fine, but I need to extend that image so I can include configuration files for my CubeJS instance, here is my docker file:

FROM cubejs/cube:v0.33.33
FROM --platform=linux/amd64 node:lts-alpine
COPY . .
RUN apk update && apk add py-pip
RUN npm install

I run a build on the above and then push it, in AWS Fargate I use that newly pushed repo in the Fargate Json File, but when deploying nothing runs, what am I missing?