Woocommerce Plugin must be installed.
You can make wocommerce checkout required fields optional or optional fields required in woocommerce
After Plugin Installed, Go to "Checkout Fields Setting" from admin left menu, then adjust changes as per your need and save the setting.
安装:
First Install woocommerce Plugin
Then instal this(Make Checkout fields optional - Technogiq) plugin. Just download and install like any other wordpress plugins.