That is likely to be a problem for you. The condenser fan in the outdoor unit is designed to operate in an open environment. It very likely cannot tolerate the airflow restriction imposed by mounting internally. you might be able to do so with the use of external fans to provide airflow to and from the unit if you bury it in an enclosed space.
Many of the units come with an exterior wall mount bracket, with the back only an inch or two at most from the wall, with the fan pointing out. The ruggedized, dedicated over-the-road unit that I found has the fan and condenser separated. I’m discovering that it’s very doable but dealing with the condensate will be a big deal, especially so in a humid climate. It will throw off so much water, I’m wondering if running it through a filter with antimicrobial piping might not keep the potable water tank filled most of the time.