How to force Docker to run my script using bash, and not sh

This is my script:

#!/bin/bash

# some bash code here

And this is my Dockerfile:

FROM node:lts-bullseye-slim
COPY . .
RUN /Script.sh

And here's the error I get:

Step 5/5 : RUN /Script.sh
 ---> Running in 09bbdebbc3d7
/Script.sh: line 25: syntax error: unexpected end of file
The command '/bin/sh -c /Script.sh' returned a non-zero code: 2

However, if I run the container in the interactive mode and enter it using docker exec -it container_name bash and run the script, it works.

I think it fails in the build process because Docker wants to use sh and not bash.

How can I force Docker to use bash, and not sh?

Update

This is my real script, and its real name is BuildScript and it has no extensions and it's in the root directory and it has 777 permission:

#!/bin/bash

function RemoveDevelopmentItems()
{
    echo "Removing development items ..."
    rm -rf ${RepositoryPath}/Host
}

function BuildDirectories()
{
    echo "Building directories ..."
    mkdir -p ${RepositoryPath}/src
    mkdir -p ${RepositoryPath}/public
    mkdir -p ${RepositoryPath}/public/favicons
    mkdir -p ${RepositoryPath}/public/Fonts
    mkdir -p ${RepositoryPath}/src/Base
    mkdir -p ${RepositoryPath}/src/Contexts
    mkdir -p ${RepositoryPath}/src/Components
    mkdir -p ${RepositoryPath}/src/Hooks
    mkdir -p ${RepositoryPath}/src/Panel
}

function CopyCommon()
{
    echo "Copying common ..."
    cp -a /${Organization}/Common/Branding/Favicons/* ${RepositoryPath}/public/favicons
    cp -r /${Organization}/Common/Branding ${RepositoryPath}/src/Branding
    cp -r /${Organization}/Common/Logo.jsx ${RepositoryPath}/src/Logo.jsx
}

function CopyBase()
{
    echo "Copying base ..."
    cp -r /HolismPanel/Infra/src/Base ${RepositoryPath}/src
    cp -r /HolismPanel/Infra/src/Components ${RepositoryPath}/src
    cp -r /HolismPanel/Infra/src/Contexts ${RepositoryPath}/src
    cp -r /HolismPanel/Infra/src/Fonts ${RepositoryPath}/public
    cp -r /HolismPanel/Infra/src/Hooks ${RepositoryPath}/src
    cp -r /HolismPanel/Infra/src/Panel ${RepositoryPath}/src
    cp /HolismPanel/Infra/index.html ${RepositoryPath}/index.html
    cp /HolismPanel/Infra/package.json ${RepositoryPath}
    cp /HolismPanel/Infra/postcss.config.js ${RepositoryPath}
    cp /HolismPanel/Infra/src/index.css ${RepositoryPath}/src
    cp /HolismPanel/Infra/src/main.jsx ${RepositoryPath}/src
    cp /HolismPanel/Infra/tailwind.config.js ${RepositoryPath}
    cp /HolismPanel/Infra/vite.config.js ${RepositoryPath}
}

function CopyDependencies()
{
    echo "Copying dependencies ..."
    find /HolismPanel -mindepth 1 -maxdepth 1 -not -name Infra |
    while read DependencyPath;
    do
        DependencyName=$(basename $DependencyPath);
        if [[ ${Repository} == *Admin* ]]; then
            mkdir -p ${RepositoryPath}/src/$DependencyName
            cp -a /HolismPanel/$DependencyName/Admin/* ${RepositoryPath}/src/$DependencyName
        fi
    done
}

function MoveMainRepoFiles()
{
    echo "Moving main repo files ..."
    mv ${RepositoryPath}/Menu.jsx ${RepositoryPath}/src/Menu.jsx
    mv ${RepositoryPath}/Routes.jsx ${RepositoryPath}/src/Routes.jsx
    mv ${RepositoryPath}/HeaderActions.jsx ${RepositoryPath}/src/HeaderActions.jsx
    find ${RepositoryPath} -mindepth 1 -maxdepth 1 -type d -not -name src -not -name public |
    while read MainRepoDirectory;
    do
        mv $MainRepoDirectory ${RepositoryPath}/src
    done
}

function LinkNodeModules()
{
    echo "Linking node_modules ..."
    ln -s /HolismPanel/Infra/node_modules ${RepositoryPath}
}

RemoveDevelopmentItems
BuildDirectories
CopyCommon
CopyBase
CopyDependencies
MoveMainRepoFiles
LinkNodeModules

And please don't tell me that you should add an extension, or not make 777 files, or not work in the root directory. Thank you.