<?php
...
    public function getanggota($no_kk){
        $kk = detail_kartukeluarga::where('no_kk', $no_kk)->first();
		if ($kk) {
			return response()->json($kk->detail); // tapi detail harus relasi hasMany, bukan hasOne
		}
		return response()->json(collect(['pesan' => 'tidak ada data']));
    }
...