Just for information, follow my solution with O(N+M) complexity, where n is teh size of stringList and M is the size of query list

function matchingStrings(stringList: string[],queries: string[]): number[]{ const MatchCountMap = new Map(); const frequences: number[] = [];

for(const word of stringList){
    const wordCount = MatchCountMap.get(word) ?? 0;
    MatchCountMap.set(word,wordCount+1);
}

for (const word of queries){
  const wordCount = MatchCountMap.get(word)
    frequences.push(wordCount ?? 0)
}
return  frequences;

}