You may need to modify your WordPress site’s php.ini file, which is the default PHP configuration file, to increase the site’s Memory Limit, Maximum Execution Time, Maximum Input Time etc. However, there is no access to the php.ini file in an Azure hosted WordPress Web App!

A simple solution is to add a .user.ini file to the site/wwwroot folder via the Kudu site of your website. Read more about Kudu here

Portal > Web App > Development Tools > Advanced Tools  blade > Go > Debug Console > cmd > site > wwwroot > + file > .user.ini

Add the following settings: