Arabic keyboards lack many important special characters. Here is a list of the most important characters and signs which you can copy and paste.
The word Allah is often written like a calligraphy - with the dagger Aleph. There are several ways to achieve that in Microsoft Word or Libre Office.
Many students are confused why words like هذا, ذلك or لكن are written with a dash (dagger Aleph). Should they be pronounced with a long vowel ("aa")? Yes.