Trying to install vtiger

[maxus23]

Hi! I'm trying to install vtiger 6.5 or 7.1:
cd /opt
git clone https://github.com/javanile/vtiger.git
cd /opt/vtiger
./develop.sh 6.5.0

but then i'm getting an error:
=> ERROR [ 6/22] RUN apt-get update && apt-get install --no-install-recommends -y zlib1g-dev libc-client-dev libkrb5-dev libfreetype 4.6s

[ 6/22] RUN apt-get update && apt-get install --no-install-recommends -y zlib1g-dev libc-client-dev libkrb5-dev libfreetype6-dev libjpeg62-turbo-dev libpng-dev libxml2-dev cron rsyslog zip unzip socat vim nano && docker-php-ext-configure gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/ && docker-php-ext-configure imap --with-kerberos --with-imap-ssl && docker-php-ext-install imap exif mysqli pdo pdo_mysql zip gd xml && echo "cron.* /var/log/cron.log" >> /etc/rsyslog.conf && rm -fr /etc/cron.* && mkdir /etc/cron.d && true:
1.213 Ign:1 http://security.debian.org/debian-security stretch/updates InRelease
1.258 Ign:2 http://deb.debian.org/debian stretch InRelease
1.281 Ign:3 http://security.debian.org/debian-security stretch/updates Release
1.326 Ign:4 http://deb.debian.org/debian stretch-updates InRelease
1.351 Ign:5 http://security.debian.org/debian-security stretch/updates/main all Packages

3.390 W: The repository 'http://security.debian.org/debian-security stretch/updates Release' does not have a Release file.
3.390 W: The repository 'http://deb.debian.org/debian stretch Release' does not have a Release file.
3.390 W: The repository 'http://deb.debian.org/debian stretch-updates Release' does not have a Release file.
3.390 E: Failed to fetch http://security.debian.org/debian-security/dists/stretch/updates/main/binary-amd64/Packages 404 Not Found [IP: 151.101.2.132 80]
3.390 E: Failed to fetch http://deb.debian.org/debian/dists/stretch/main/binary-amd64/Packages 404 Not Found [IP: 151.101.66.132 80]
3.390 E: Failed to fetch http://deb.debian.org/debian/dists/stretch-updates/main/binary-amd64/Packages 404 Not Found [IP: 151.101.66.132 80]
3.390 E: Some index files failed to download. They have been ignored, or old ones used instead.

It looks like the script is trying to get updates to debian 9 stretch, not the latest debian 12 repository.