See for example how zenkit does them
⭐️ I have merged your post with this post #2570 already covering this request. Feel free to add your comments to that thread.
Peggy, Feb 3, 2021
Hi @joseq - Having custom fields feature is in our plan for our future improvements. I will add your suggestion to our internal list and let you know when we have an update for this feature.
⭐️ I have merged your post with this post #2570 already covering this request. Feel free to add your comments to that thread.
Peggy, Feb 3, 2021