How can I append value to the local variable but not re write it

Hi all!
Im wondering is anyway to append new value to environment variable without it been rewritted all.

I have an array let usedInLists = ;

which I initialize in the end of each request cycle ( postman.setNextRequest(“Check if userID is in a list”) with need data [“string0”, “string1”, … ]

like this
pm.environment.set(“usedInLists”, usedInLists);

but each time this request has been triggered I have completely new value but I want to see

[“string0”, “string1”, … ] + […“string4”, "string5]