Kowsar Hossain

If you want to make coupon code as a required field, this plugin will help.
During checkout when a customer will try to place an order without entering any coupon code, checkout process will be interrupted and customer will see an error notice.
You can configure the error notice text from “WooCommerce>Force Coupon” menu from admin panel.

Force Coupon for WooCommerce

A lightweight WooCommerce based plugin to force the customer to enter a coupon code during checkout

Jan Štětina

Forces all users to have a strong password when they’re changing it on their profile page. If user enters a weak password an error message is displayed.
It uses the same algorithm to determine password strength as WordPress.
On multisite, network administrator can define required password strength (Network Admin –> Settings –> Enforce Strong Passwords). On single site it’s admin has this capability (Options –> Enforce Strong Passwords).
Developed for private use, but has perspective for more extensive usage. I can’t guarantee any support in the future nor further development, but it is to be expected. Kindly inform me about bugs, if you find any, or propose new features: <a href="mailto:zaantar@zaantar.eu?subject=[enforce-strong-password]" rel="nofollow ugc">zaantar@zaantar.eu</a>.

Enforce Strong Password

Forces all users to have a strong password when they're changing it on their profile page.

Force Coupon for WooCommerce vs Enforce Strong Password