This will print the last updated date for each installed plugin. Note that this script assumes that you're in the WordPress root directory where the wp command works.
WP-CLI installed and accessible via wp.
jq for parsing JSON. Install it via sudo apt install jq
curl for making HTTP requests.
Install it via sudo apt install curl
Download or save the above script in a file, called get_plugins_last_updated.sh.
Upload to server in WP root
Make the script executable:
chmod +x get_plugins_last_updated.sh
Run the script:
sudo -u www-data ./get_plugins_last_updated.sh