Is exposure lock without phone attached possible?

Hi, thank you for bringing this query to us. This option is only available if you have a mobile device connected to the unit. Therefore, we cannot lock the exposure using the unit only. Thank you for your understanding and support!

Surely in Pro mode you can access the manual settings in the top left corner of the screen and choose ISO, and shutter speed manually. As the aperture is fixed that should lock the exposure. OK, you don't get zebra striping to aid the exposure setting but it is a manual lock down of the exposure even if it is difficult to assess on such a small screen you do get a bar reading of exposure.