Prep Plugin for release on WordPress.org

Escape everything that should be escaped.
Add nonce checks where needed.
Sanitize all inputs.
Apply Code style changes across the codebase.
Correct many deprecation notices.
Optimize load order of many filters.

inc/checkout/class-legacy-checkout.php

@@ -1018,7 +1018,7 @@ class Legacy_Checkout {
 	public function next_step($args = []): void {
 
 		/** Redirect the user to the next step */
-		wp_redirect(esc_url_raw($this->get_next_step_link($args)));
+		wp_safe_redirect(esc_url_raw($this->get_next_step_link($args)));
 
 		/** Kill the execution after the redirect */
 		exit;