Alter JSON code to disallow new tab to open

Beth_Culpepper Try changing target attribute to _self like: 

{
  "$schema": "https://developer.microsoft.com/json-schemas/sp/v2/row-formatting.schema.json",
  "hideSelection": true,
  "hideColumnHeader": true,
  "rowFormatter": {
    "elmType": "div",
    "style": {
      "position": "absolute",
      "width": "150px",
      "height": "150px",
      "left": "=if(floor(@rowIndex/5) % 2 == 0 , @rowIndex % 5 * 150 + 'px' , @rowIndex % 5 * 150 + 75 + 'px' )",
      "top": "=floor(@rowIndex / 5) * 125 + 'px'"
    },
    "children": [
      {
        "elmType": "a",
        "style": {
          "position": "relative",
          "display": "flex",
          "justify-content": "center",
          "align-items": "center",
          "width": "100%",
          "height": "100%"
        },
        "attributes": {
          "href": "[$URL]",
          "target": "_self",
          "class": "ms-fontColor-themePrimary ms-fontColor-themeDark--hover"
        },
        "children": [
          {
            "elmType": "svg",
            "style": {
              "fill": "currentColor",
              "cursor": "pointer"
            },
            "attributes": {
              "viewBox": "-150 -150 300 300"
            },
            "children": [
              {
                "elmType": "path",
                "attributes": {
                  "d": "M130 75 L0 150 L-130 75 L-130 -75 L-0 -150 L130 -75 z"
                }
              }
            ]
          },
          {
            "elmType": "div",
            "style": {
              "position": "absolute",
              "display": "flex",
              "flex-direction": "column",
              "align-items": "center",
              "justify-content": "center",
              "cursor": "pointer",
              "width": "100%",
              "height": "100%"
            },
            "attributes": {
              "class": "ms-fontColor-white"
            },
            "children": [
              {
                "elmType": "div",
                "style": {
                  "font-size": "32px",
                  "margin-bottom": "5px"
                },
                "attributes": {
                  "iconName": "[$Icon]"
                }
              },
              {
                "elmType": "div",
                "style": {
                  "font-size": "14px",
                  "width": "75%",
                  "text-align": "center"
                },
                "txtContent": "[$Title]"
              }
            ]
          }
        ]
      }
    ]
  }
}

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