There have been several discussions and questions about footprints like this, I think it’s usually called a membrane switch. By doing a forum search with “membrane” I found for example this: Membrane pattern cannot be connected. There’s a footprint file there which you can probably use as a starting point.
As a general rule, you have to create two custom pads from graphic shapes. See for example Create Pad from Selected shapes disappear in KiCad V7.01? - #2 by mf_ibfeew.