Great to hear you got it working.
You can try with the ordinary tls-crypt (v1) key, make a simple static key and use that for both server and client like:
<tls-crypt>
-----BEGIN OpenVPN Static key V1-----
XXXXXXXXXXXXXXXXXXXXX
-----END OpenVPN Static key V1-----
</tls-crypt>
If your problem is solved, please consider marking this topic as [Solved]. See How to mark a topic as [Solved] for a short how-to.
Thanks! 