"phải biết" meaning in Vietnamien

{
  "categories": [
    {
      "kind": "other",
      "name": "Adverbes en vietnamien",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Vietnamien",
      "orig": "vietnamien",
      "parents": [],
      "source": "w"
    }
  ],
  "lang": "Vietnamien",
  "lang_code": "vi",
  "pos": "adv",
  "pos_title": "Adverbe",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Exemples en vietnamien",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Termes vulgaires en vietnamien",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "Ngon phải biết",
          "translation": "Extrêmement délicieux"
        }
      ],
      "glosses": [
        "Extrêmement."
      ],
      "id": "fr-phải_biết-vi-adv-XaUVbGXx",
      "tags": [
        "vulgar"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "\\fai˧˨˧.bjet˦\\"
    }
  ],
  "word": "phải biết"
}

{
  "categories": [
    "Adverbes en vietnamien",
    "vietnamien"
  ],
  "lang": "Vietnamien",
  "lang_code": "vi",
  "pos": "adv",
  "pos_title": "Adverbe",
  "senses": [
    {
      "categories": [
        "Exemples en vietnamien",
        "Termes vulgaires en vietnamien"
      ],
      "examples": [
        {
          "text": "Ngon phải biết",
          "translation": "Extrêmement délicieux"
        }
      ],
      "glosses": [
        "Extrêmement."
      ],
      "tags": [
        "vulgar"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "\\fai˧˨˧.bjet˦\\"
    }
  ],
  "word": "phải biết"
}