Yes, it is possible to use overlays in org beamer export. Depending on what you want to achieve, there are a number of ways to do this. One way in to introduce LaTeX directives directly. For instance,
#+begin_src org
1. The first point
2. The second one @@latex:{\only<2->\checkmark}@@
3. the third point
#+end_src
There are also other examples in section 13.8.4 (Beamer specific syntax)
in the info manual.
HTH.
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Eric S Fraga via Emacs 27.0.50, Org release_9.2.4-401-gfabd6d
