Conditional formatting using JSON
I have tried to customise a column using JSON script lifted from this site https://docs.microsoft.com/en-us/sharepoint/dev/declarative-customization/column-formatting#apply-conditional-formatting and have viewed numerous YouTube videos of people just copying and pasting this code into the Edit columns settings and it just working. Nothing happens for me however, is there a setting at a high level that needs to be switched on to allow JSON formatting to work?