Simplify paid level checkouts by removing Account Information section and generating username and password.

simple_paid_checkout_signup.php

<?php
/**
 * Simplify paid level checkouts by removing Account Information section and generating username and password.
 * You must be capturing full Billing Information for this recipe to work.
 */

/**
 * Hide the Account Information Section
 */
function simple_checkout_hide_account_information_section( $skip_account_fields, $current_user ) {
	if ( empty( $current_user->ID ) ) {
		$skip_account_fields = 1;
	}
	return $skip_account_fields;
}
add_filter( 'pmpro_skip_account_fields', 'simple_checkout_hide_account_information_section', 10, 2 );

/**
 * Unset required account fields, we'll use Register Helper to require our new fields.
 */
function my_required_user_fields( $pmpro_required_user_fields ) {
	unset( $pmpro_required_user_fields['username'] );
	unset( $pmpro_required_user_fields['password'] );
	unset( $pmpro_required_user_fields['password2'] );
	unset( $pmpro_required_user_fields['bconfirmemail'] );
	
	return $pmpro_required_user_fields;
}
add_filter( 'pmpro_required_user_fields', 'my_required_user_fields', 10, 2);

/**
 * Don't include the "confirm email" field in Billing Information
 */
add_filter( 'pmpro_checkout_confirm_email', '__return_false' );

This recipe is included in the blog post on "Increase Conversion Rates with a Simplified Checkout" at Paid Memberships Pro here: https://www.paidmembershipspro.com/increase-conversion-rates-with-a-simplified-checkout/