Pix-Art Messenger will remove the implementation of OTR encryption by 30th June of 2020 with version 2.5.0.
Unfortunately, it does not make sense to continue support on a rather out-dated technology, even as we see some users keep using it. For the moment, OTR (as well as OpenPGP) can be activated via the expert settings for advanced users. Pix-Art Messenger always tries to be usable for even non-technical users, OTR however is not counted as appropriate for this.
Please consider to use OMEMO in the future, many other clients has implemented this, have a look at omemo.top. However, if you really need to continue using it, please refer to e.g. Miranda, Pidgin plugin, Profanity or Coy.im. You are also able to fork Pix-Art Messenger and continue the implementation on your own.
Please consider the differences between encryption protocols and also advantages of OMEMO:Source: [https://conversations.im/omemo](https://conversations.im/omemo)
Some limitations of OTR: wikipedia.org/wiki/Off-the-Record
Please inform your contacts who may also use it.