The command 'dotnet' not found in Dockerfile - node.js

Question

I trie to build an image with docker to run a project, but When i run docker build, the step 5/12:
/bin/sh: 1: dotnet: not found
The command '/bin/sh -c dotnet restore' returned a non-zero code: 127
Note: I'm running .Net Core and Node Modules, so i put all in the Dockerfile, is that OK? I'm new with Docker
This is my dockerfile:
# Otenemos el SDK de .Net Core en la versión 2.1
FROM microsoft/dotnet:2.1-sdk
FROM node:11
WORKDIR /FrontEnd
#Copiamos el archivo .csproj y restauramos paquetes.
COPY *.csproj ./
RUN dotnet restore
COPY package.json ./
RUN npm install
# Copiamos todo lo demás
COPY . ./
FROM microsoft/dotnet:2.1-aspnetcore-runtime
WORKDIR /FrontEnd
ENTRYPOINT [ "dotnet", "run" ]
EDIT
This is my new Dockerfile
Seems working in console, but in Chrome doesn't.
This is the command that i run in console:
docker run --rm name_proj:latest
FROM microsoft/dotnet:2.1-sdk AS build
WORKDIR /FrontEnd
COPY *.csproj ./
COPY package.json ./
RUN dotnet restore
RUN apt-get update -yq && apt-get upgrade -yq && apt-get install -yq curl git nano
RUN curl -sL https://deb.nodesource.com/setup_11.x | bash - && apt-get install -yq nodejs build-essential
RUN npm install -g npm
RUN npm install
COPY . ./
#FROM microsoft/dotnet:2.1-aspnetcore-runtime
ENTRYPOINT [ "dotnet", "run" ]
The log in console:
When i open localhost:5001 is not working

Answer 1

You can only inherit from one container via FROM. Every time you use a FROM, you are switching to using a new container as the base. When you do
FROM microsoft/dotnet:2.1-sdk
FROM node:11
The effect is the same as just
FROM node:11
And in the node contianer, there's no .NET Core installed.
If you want a contianer where both dotnet and npm commands are available, you need to build it yourself. Here's an answer on stackoverflow that shows you how do to that: How to integrate 'npm install' into ASP.NET CORE 2.1 Docker build. The short version is that you start from one container (maybe FROM microsoft/dotnet:2.1-sdk) and you install the node packages into it manually.