Check your wp-config.php file to see what your memory limit is set at and increase it. If not noted add this line to your wp-config.php file:
define( 'WP_MEMORY_LIMIT', '256M' );
More info on this file and memory here. https://codex.wordpress.org/Editing_wp-config.php#Increasing_memory_allocated_to_PHP
Hmmm... I was able to do so when I used that platform... Just basing my response on what I have and was able to do. (?) If GoDaddy has now restricted that (maybe someone can confirm?) -- then you need to contact support for further help.
Would like to know the same. And if Godaddy keeps adding limitations on managed wordpress hosting, I would like to be notified.
GoDaddy Managed WordPress platform gives users no access to cPanel, so this is not a valid solution. GoDaddy expects their users to utilize sFTP access which is cumbersome to use, & is a poor option for the user if they are not familiar with how to use it.