excat

=ArrayFormula(let(
 symbols;LAMBDA(from;to;ArrayFormula(JOIN(;СИМВОЛ(SEQUENCE(abs(КОДСИМВ(to)-КОДСИМВ(from))+1;1;МИН(КОДСИМВ(from);КОДСИМВ(to)))))));
 
 alphabetEn;symbols("a";"z")&symbols("A";"Z");
 alphabetRu;symbols("а";"я")&symbols("А";"Я")&"ёЁ";
 specString;"!""№;%:?*()_+@#$%^&*\|/.,-='{}[]<>`~"; 
 numbers;"0123456789";
 
 generate;lambda(fromText;count;join("";ПСТР(fromText;ОКРУГЛВВЕРХ(randarray(count)*ДЛСТР(fromText));1)));