Woocommerce + Google Analytics (Conversion Rate Not Working)

I am using WC (Version 5.7.1) WooCommerce Google Analytics Integration (Version 1.5.3), the setup between Google Analytics and my WC website goes well so far, except the conversion rate is not calculated at all, and I guess the problem because we don't redirect the user to a thank you page where it redirects to /checkout/order-received/order-number/?key=wc_order_key instead.

I would appreciate it if someone could help us in how we could notify Google Analytics that the checkout process is done in order to get the conversion rate works on Google Analytics.

Thanks.