giving permissions to storage folder using laravel sail

This is my default docker file generated from sail package i'm new to docker and i don't know when exactly the project is copied into /var/www/html directory to execute the permission

where do i put my permissions here's my docker file

FROM ubuntu:20.04

LABEL maintainer="Taylor Otwell"

ARG WWWGROUP

WORKDIR /var/www/html

ENV DEBIAN_FRONTEND noninteractive
ENV TZ=UTC

RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
RUN apt-get update && apt-get install -y cron
RUN apt-get update \
    && apt-get install -y gnupg gosu curl ca-certificates zip unzip git supervisor sqlite3 libcap2-bin libpng-dev python2 \
    && mkdir -p ~/.gnupg \
    && chmod 600 ~/.gnupg \
    && echo "disable-ipv6" >> ~/.gnupg/dirmngr.conf \
    && apt-key adv --homedir ~/.gnupg --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys E5267A6C \
    && apt-key adv --homedir ~/.gnupg --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys C300EE8C \
    && echo "deb http://ppa.launchpad.net/ondrej/php/ubuntu focal main" > /etc/apt/sources.list.d/ppa_ondrej_php.list \
    && apt-get update \
    && apt-get install -y php8.0-cli php8.0-dev \
       php8.0-pgsql php8.0-sqlite3 php8.0-gd \
       php8.0-curl php8.0-memcached \
       php8.0-imap php8.0-mysql php8.0-mbstring \
       php8.0-xml php8.0-zip php8.0-bcmath php8.0-soap \
       php8.0-intl php8.0-readline \
       php8.0-msgpack php8.0-igbinary php8.0-ldap \
       php8.0-redis \
    && php -r "readfile('http://getcomposer.org/installer');" | php -- --install-dir=/usr/bin/ --filename=composer \
    && curl -sL https://deb.nodesource.com/setup_15.x | bash - \
    && apt-get install -y nodejs \
    && curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | apt-key add - \
    && echo "deb https://dl.yarnpkg.com/debian/ stable main" > /etc/apt/sources.list.d/yarn.list \
    && apt-get update \
    && apt-get install -y yarn \
    && apt-get install -y mysql-client \
    && apt-get install -y postgresql-client \ 
    && apt install nano \
    && apt-get -y autoremove \
    && apt-get clean \
    && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*

RUN apt-get update && apt-get install -y cron

RUN pecl install swoole

RUN setcap "cap_net_bind_service=+ep" /usr/bin/php8.0
RUN groupadd --force -g $WWWGROUP sail
RUN useradd -ms /bin/bash --no-user-group -g $WWWGROUP -u 1337 sail

COPY start-container /usr/local/bin/start-container
COPY supervisord.conf /etc/supervisor/conf.d/supervisord.conf
COPY php.ini /etc/php/8.0/cli/conf.d/99-sail.ini
 
RUN chmod +x /usr/local/bin/start-container

COPY crontab /etc/cron.d/crontab
RUN chown /etc/cron.d/crontab \
    && crontab /etc/cron.d/crontab \
    && touch /var/log/cron.log

RUN cd /var/www/html && service cron start 

RUN cd /var/www/html && chmod 777 -R ./storage && chmod 777 -R ./bootstrap/cache && chmod 777 -R ./public/images/pictures 

EXPOSE 8000

ENTRYPOINT ["start-container"]