Create a custom confirmation with a custom message if the user still requires to confirm their email

my-pmpro-confirmation-message.php

<?php

/**
 * This recipe changes the default confirmation message when a user checks out.
 *
 * This is adapted from https://gist.github.com/femiyb/253535512d0df7165d4cd7f9716c25f5
 * https://www.paidmembershipspro.com/custom-confirmation-page-content/
 *
 * You can add this recipe to your site by creating a custom plugin
 * or using the Code Snippets plugin available for free in the WordPress repository.
 * Read this companion article for step-by-step directions on either method.
 * https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */

remove_filter( 'pmpro_confirmation_message', 'pmpro_pmpro_confirmation_message' );

// add new confirmation text
function my_pmpro_confirmation_message( $message ) {

	global $current_user;

	$message = '';

	// Set default
	$message .= '<p>Thank you for choosing the <strong>' . pmpro_getMembershipLevelForUser( $current_user->ID )->name . '</strong> membership.</p>';

	//Custom message if email confirmation level and user's email not confirmed.
	if ( function_exists( 'pmproec_isEmailConfirmationLevel') && 0 != intval( pmpro_getMembershipLevelForUser( $current_user->ID ) ) && pmproec_isEmailConfirmationLevel( intval( pmpro_getMembershipLevelForUser( $current_user->ID )->ID ) ) ) {

		if ( $current_user->pmpro_email_confirmation_key != 'validated' ) {

			$message .= '<p>We sent an email to <strong>' . $current_user->user_email . '</strong>. Please check your inbox and confirm your email. Once it’s done you will be able to activate your <strong>' . pmpro_getMembershipLevelForUser( $current_user->ID )->name . '</strong> membership.</p>';
		}
	}

	return $message;
}
add_filter( 'pmpro_confirmation_message', 'my_pmpro_confirmation_message', 20, 1 );