In order to increase the WordPress memory limit, you must edit the WordPress
Connect to your SFTP server using (see how to connect using Cyberduck)
Within the /public_html/ folder locate wp-config.php
Right-click on the file and select Edit
Paste the directive code
above /* That's all, stop editing! Happy blogging. */
Once you are done making changes save the file. The downloaded file will then upload to back to the server and override the existing file.