Install extensions for PHP 7.4 on Ubuntu 20

sudo apt-get install php7.4-cli php7.4-fpm php7.4-bcmath php7.4-curl php7.4-gd php7.4-intl php7.4-json php7.4-mbstring php7.4-mysql php7.4-opcache php7.4-sqlite3 php7.4-xml php7.4-zip

or 

sudo apt update

sudo apt install php7.4

sudo apt install php7.4-common php7.4-mysql php7.4-xml php7.4-xmlrpc php7.4-curl php7.4-gd php7.4-imagick php7.4-cli php7.4-dev php7.4-imap php7.4-mbstring php7.4-opcache php7.4-soap php7.4-zip php7.4-intl -y

Pass value from parent to child window in php

parent.php <?php $userid=37; echo "<form><input name=\"$userid\" align=\"center\" class=\"button btn btn-primary\" type=\"button\" onclick=\"window.open('popup.php?id='+$userid,'windowfrm','menubar=yes,toolbar=yes,scrollbars=yes,resizable=yes,width=783,height=auto')\" value=\"Printable Version\"></div>\n</form>\n\n"; ?> popup.php <?php $userid = $_GET['id']; echo $userid; ?>