Thank you, everyone. Those links work and not work. But they are helpful (I attached the screenshot). I asked Affinity about this in Twitter and this is their response: "These will require a major rewrite of the code base so at the moment there are no plans to introduce right to left text support but we may introduce this in the future." and when I asked why this feature has a low priority, they said: "It's a complex feature to add to our apps but it's on our developers todo list for the future. When we have an update, we'll let everyone know." So, I don't think they will add this feature soon. I switched from Adobe to Affinity in 2016 and it's a little sad to see they still keep us waiting. I hope they add it soon!
Here is the link: