Hello, Gewoonbovenaan,
We have thoroughly checked the situation with emails.
According to your screenshot -> https://gyazo.com/7c4f83ac8ad4eb933a4f5ac1bf96a905 we see that you are going to use another Email customizer which is differ from our built-in Email builder. Secondly, such order number which shown on the example does not exist on your web-site.
Also, we see that for now, you have deactivated our built-in Email builder, so we are interested if you are planning to use our Email editor or use that extra editor we see on the screenshot.
Kind Regards,
8theme team