Translate word “ESSENTIAL” from English to Russian

crucial necessary key vital indispensable needed required called for requisite important all-important vitally important of the utmost importance of great consequence of the essence critical life-and-death imperative mandatory compulsory obligatory compelling urgent pressing burning acute paramount preeminent high-priority significant consequential

necessity necessary/essential item prerequisite requisite requirement need condition precondition specification stipulation qualification desideratum sine qua non