Maybe set the GiveWP cookie needed for the Donor Dashboard on Multisite subsites (when GiveWP is not network activated)

givewp-multisite-cookie.php

<?php

/**
 * Maybe set the GiveWP cookie needed for the Donor Dashboard on Multisite subsites (when GiveWP is not network activated).
 */
function my_subdomain_set_givewp_cookie() {
	// Only run this if we are on the correct GiveWP subdomain site.
	if ( 123 !== get_current_blog_id() ) {
		return;
	}

	// Skip if not logged in.
	if ( ! is_user_logged_in() ) {
		return;
	}

	$give = give();

	// Skip if not logged in.
	if ( ! is_user_logged_in() ) {
		return;
	}

	$give = give();

	/*
	 * Normal WP logins do not get used for WP REST API requests so anything relying on get_current_user_id()
	 * will fail if valid REST API _wpnonce is not passed into REST API requests. GiveWP does not use this yet,
	 * so this code is a hackaround.
	 */

	// Check if we have the cookie we need.
	if ( ! $give->session->has_session() ) {
		// Force set the cookie for Donor Dashboard.
		$give->session->set_session_cookies( true );
	}

	// Allow email-based donor access for current user matching their email.
	$history_access = (bool) $give->session->get( 'history_access' );
	$session_email  = $give->session->get( 'give_email' );

	if ( empty( $session_email ) || ! $history_access ) {
		$current_user = wp_get_current_user();

		if ( $current_user ) {
			$give->session->set( 'history_access', 1 );
			$give->session->set( 'give_email', $current_user->user_email );
		}
	}
}

add_action( 'init', 'my_subdomain_set_givewp_cookie', 20 );