Model is printable without any support, should be printed from temperature resistant filement like PET-G or ASA.
Base part, redrill holes, insert M3 nuts and glue to the bottom of bay with nutn on bottom.
To mount part redrill hole, insert M3 nut and fill remaining cavity with nut lock (some glue will keep one in place). Screw to base part with two short M3 screws.
Insert airunit, put antenna cables into rails and secure them with zip ties.
Put top cover and with use angled washer to put M3 screw straight.
In case of crash reprint mount part.
The author hasn't provided the model origin yet.