Why im response "ja" language only?

This looks like you are using a library.

So not sure what the library actually called.

Using the Twitch CLI I can see this is for Apex legends.

twitch api get 'clips?game_id=511224'
{
  "data": [
    {
      "broadcaster_id": "49207184",
      "broadcaster_name": "fps_shaka",
      "created_at": "2020-06-07T13:43:24Z",
      "creator_id": "195067388",
      "creator_name": "Riki156",
      "duration": 29.8,
      "embed_url": "https://clips.twitch.tv/embed?clip=ShortIntelligentKeyboardBleedPurple",
      "game_id": "511224",
      "id": "ShortIntelligentKeyboardBleedPurple",
      "language": "ja",
      "thumbnail_url": "https://clips-media-assets2.twitch.tv/38531773792-offset-12820-preview-480x272.jpg",
      "title": "【悲報】釈迦、漏らす",
      "url": "https://clips.twitch.tv/ShortIntelligentKeyboardBleedPurple",
      "video_id": "",
      "view_count": 1857016
    },
    {
      "broadcaster_id": "98615833",
      "broadcaster_name": "ottr",
      "created_at": "2019-07-25T03:48:49Z",
      "creator_id": "72466644",
      "creator_name": "baducca_",
      "duration": 37.4,
      "embed_url": "https://clips.twitch.tv/embed?clip=SmoothShinyPterodactylPupper",
      "game_id": "511224",
      "id": "SmoothShinyPterodactylPupper",
      "language": "en",
      "thumbnail_url": "https://clips-media-assets2.twitch.tv/AT-cm%7C501249871-preview-480x272.jpg",
      "title": "LOVE_FuryXD Dies!?!",
      "url": "https://clips.twitch.tv/SmoothShinyPterodactylPupper",
      "video_id": "",
      "view_count": 449426
    },
    {
      "broadcaster_id": "197886470",
      "broadcaster_name": "TwitchRivals",
      "created_at": "2019-02-12T22:13:44Z",
      "creator_id": "28863603",
      "creator_name": "anthax77",
      "duration": 34.7,
      "embed_url": "https://clips.twitch.tv/embed?clip=CogentTubularSquirrelMau5",
      "game_id": "511224",
      "id": "CogentTubularSquirrelMau5",
      "language": "en",
      "thumbnail_url": "https://clips-media-assets2.twitch.tv/AT-cm%7C398627174-preview-480x272.jpg",
      "title": "Shroud talking about the Rivals format",
      "url": "https://clips.twitch.tv/CogentTubularSquirrelMau5",
      "video_id": "379505965",
      "view_count": 324856
    },
    {
      "broadcaster_id": "219130577",
      "broadcaster_name": "toeyouup",
      "created_at": "2019-02-09T20:40:48Z",
      "creator_id": "219130577",
      "creator_name": "toeyouup",
      "duration": 28.8,
      "embed_url": "https://clips.twitch.tv/embed?clip=PluckyGiftedWaffleBuddhaBar",
      "game_id": "511224",
      "id": "PluckyGiftedWaffleBuddhaBar",
      "language": "en",
      "thumbnail_url": "https://clips-media-assets2.twitch.tv/AT-cm%7C396612218-preview-480x272.jpg",
      "title": "The 1st win...",
      "url": "https://clips.twitch.tv/PluckyGiftedWaffleBuddhaBar",
      "video_id": "",
      "view_count": 313875
    },

I am seeing a mix of languages. Note I didn’t supply a start/end times. Since I don’t know what start/end times you used.

So I would suggest that your time restraints rolled 5 clips from japanese streamers.