Customize Email Acess link tag {email_access_link}

email_access_link.php

<?php 
add_filter('give_email_tag_email_access_link', 'custom_email_access_tag_link', 10, 2);
function custom_email_access_tag_link( $email_access_link, $tag_args ) {

		// Set email access link if donor exist.
		if ( ! empty( $tag_args['donor_id'] ) && $tag_args['verify_key'] ) {
			$donor_id = absint( $tag_args['donor_id'] );

			$access_url = add_query_arg(
				array(
					'give_nl' => $tag_args['verify_key'],
				),
				give_get_history_page_uri()
			);

			// Add donation id to email access url, if it exists.
			if ( ! empty( $_GET['donation_id'] ) ) {
				$access_url = add_query_arg(
					array(
						'donation_id' => give_clean( $_GET['donation_id'] ),
					),
					$access_url
				);
			}

			$email_access_link = sprintf(
				'<a href="%1$s" target="_blank" style="background: #008345;color: #ffffff !important;margin: 20px auto;padding: 12px 20px;border-radius: 3px;text-decoration: none;font-weight: 600;width: 200px;text-align: center; display:block;">%2$s</a>',
				esc_url( $access_url ),
				__( 'View your subscription donations &raquo;', 'give-recurring' )
			);
	}

	return $email_access_link;
}