I've been doing some searching, and there are probably some answers to this from people with more Zoho knowledge than me. However, I am new to Zoho so please assume zero knowledge - and my terminology may not be quite right.

My main problem is not knowing exactly what to search for to find relevant answers!

I am creating a new module, entries will have 2 checkboxes and a text field (simplified to describe functionality). I would like the text field default to "None" then if one checkbox is ticked (either) change the text field automatically to "one" and with both selected the text field should be "two".

Obviously this is very simplified, but describes everything I will need to do. I have created the module with the checkboxes and textfield, it is automatically updating the textfield that I cannot do.