For cheap and no monthly fees.  I would go with a Kasa camera.  I have these as well as my Ubiquiti cameras and for about $30 it is a decent camera.  They have some other cameras as well as doorbells.  No need to pay for their monthly service.

Kasa 2K QHD Security Camera Pan/Tilt, Starlight Sensor for Color Night Vision, Motion Detection for Baby & Pet Monitor, 2-Way Audio, Cloud & SD Card Storage, Works with Alexa & Google Home (KC410S)