Variables aren't expanded inside a script

I establish LEMP on pure Ubuntu droplets with the following script:

#!/bin/bash
ufw --force enable && ufw allow 22,25,80,443,9000/tcp
apt-get update -y && add-apt-repository ppa:certbot/certbot -y && apt-get update -y
DEBIAN_FRONTEND=noninteractive apt-get upgrade zip unzip tree unattended-upgrades sshguard postfix -y
apt-get upgrade nginx python-certbot-nginx mysql-server php-fpm php-mysql php-mbstring php-mcrypt -y
sed -i "s/post_max_size = .M/post_max_size = 200M/ ; s/upload_max_filesize = .M/upload_max_filesize = 200M/ ; s/;cgi.fix_pathinfo=1/cgi.fix_pathinfo=0/" /etc/php/*/fpm/php.ini
/etc/init.d/php*-fpm restart && systemctl restart nginx.service

wget -P ~/myAddons/ https://raw.githubusercontent.com/benqzq/unse/master/{nwsm.sh,dbm.sh,imb.sh,daily.sh,weekly.sh,appendix.sh}
curl https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli.phar > /usr/local/bin/wp
chmod +x ~/myAddons/* /usr/local/bin/wp
cat >> "/etc/bash.bashrc" <<< "source ~/myAddons/appendix.sh"
source ~/myAddons/appendix.sh /etc/bash.bashrc
echo -e "0 0 * * * ~/myAddons/daily.sh \n0 0 * * 0 ~/myAddons/weekly.sh" | crontab

wget -P ${drt}/ https://www.phpmyadmin.net/downloads/phpMyAdmin-latest-all-languages.zip
find ${drt}/ -type f -iname "*phpmyadmin*.zip" -exec unzip {} \;
find ${drt}/ -type d -iname 'phpmyadmin-*' -exec mv {} phpmyadmin \;
find ${drt}/ -type f -iname "*phpmyadmin*.zip" -exec rm {} \;
chown -R www-data:www-data ${drt}/
chmod -R a-x,a=rX,u+w ${drt}/

One can directly run the script this way:

source <(curl -s https://raw.githubusercontent.com/benqzq/unse/master/unse.sh | tr -d '\r')

The problem is that the last portion of the script regarding PHPmyadmin install, fails to run correctly — the variables aren’t expanded, hence that part of the script runs in a broken way, and I need to correct the paths after installation, to actually use PMA.

Why are the variables aren’t expanded in script execution and what will you say, is the best way to cope with that?

Thanks,