You may have noticed that the latest CalyxOS - 6.6.23 - doesn't support charge control anymore. See here for details.
This is mighty annoying, but I understand it will come back. In the meantime, if you want to limit the charge of your battery, you can use one of these little doodads.
They're not ideal because they require Bluetooth, the charge constantly flucturates some percentage points around the target charge level, and they disconnect the data link each time they cut off. But it's better than nothing until proper charge limiting is reintroduced in CalyxOS.