[wordpress] Can I install/update WordPress plugins without providing FTP access?

You can get it very easily by typing the following command on command promt

sudo chown -R www-data:www-data your_folder_name

or copy & paste the following code in your wp-config.php file.

define('FS_METHOD', 'direct');

Where "your_folder_name" is the folder where your WordPress is installed inside this folder.