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?

Thanks!