Add jars to Docker image from Plugin Directory

I have a spring boot application which contains a Main Class. I have Docker File as below:

FROM docker.io/openjdk:11-jre-slim
EXPOSE 8082
EXPOSE 8443
ADD target/base-application.jar app.jar
ENV JAVA_OPTS=""
ENTRYPOINT exec java $JAVA_OPTS -Dspring.profiles.active=prod -jar /app.jar

I am creating a Docker image by using this Docker file. Let’s consider that this docker file is Docker1 .

I have another Spring Boot application (which doesn’t have a Main class) with Docker file as below:

FROM Docker1:0.0.1
EXPOSE 8443
ADD target/child-application.jar child-application.jar
ENV JAVA_OPTS=""
ENTRYPOINT exec java $JAVA_OPTS -Dspring.profiles.active=dev -jar /app.jar

I am using Docker1 as a base image for the docker image of 2nd application. I am running the Main class of Docker1 by running 2nd Docker image. Now there are 2 jar files of another spring boot projects( messagepack1.jar & messagepack2.jar ). I want to load these jars in the 2nd docker image. I am trying something like this:

FROM Docker1:0.0.1
EXPOSE 8443
COPY src/main/resources/message-packs/messagepack1.jar m1.jar
COPY src/main/resources/message-packs/messagepack2.jar m2.jar
ADD target/child-application.jar child-application.jar
ENV JAVA_OPTS=""
ENTRYPOINT exec java $JAVA_OPTS -Dspring.profiles.active=dev -jar /app.jar

But it is not loading the jars when I am running the 2nd Docker image. Can you please help me out?