Currently, OKOMO does not offer its own system integration for text shortcuts. However, the Magical browser extension Magical is recommendable option for this. The extension is free and available for Google Chrome in the Chrome Store & Microsoft Edge in the Edge Add-Ons and also works with the OKOMO web apps.
With Magical you can easily create shortcuts, which can then be called and inserted during chat interactions by typing the shortcut or "//". Here is an example of how Magical works in the OKOMO Chrome Web App:
More info about Magical can be found in the corresponding extension store or on the Magical website