The APE-3 is best documented as support equipment inside a deployable command-post set rather than as an independently tracked combat vehicle. RusBITech's public product page identifies the smaller fixed-volume module, while delivery reporting places it alongside APE-5 command-post modules supplied to Russian formations.
Crew supportRusBITech states that APE-3 supports field work and rest for a 4-5-person group.
Set compositionCNews and DFNC describe an APE set as an APE-5 module on a KamAZ-63501 chassis plus a towed APE-3 module.
Interior fitCNews reports four workplaces, six rest places, a toilet, and a shower in the APE-3 module.
Delivery contextDFNC reported delivered and planned APE-3/APE-5 sets for Russian Western and Southern Military District formations.
Sources: RusBITech APE-3 product page; CNews RusBITech APE contract dispute; DFNC RusBITech state-defense-order report.