Conversion tracking when using API to post a lead

Hi, I would like to utilize the POST /pages/{page_id}/leads endpoint, and I see that the example request includes a conversion parameter.

"conversion": true

I have been able to create leads using this endpoint, but I can’t seem to figure out what the conversion parameter does. It seems like it should increase the conversion number (which would be great!), but it isn’t doing that. Does anyone know?