Given my result from an OCR is 123+123 how do I get it to automatically calculate it for me and type 246

Evaluating (parsing) a string as a mathematical expression can be a bit tricky in general. But for A+B it is easy. You can first split the string in two parts at the +, convert each part to an integer with parseInt and then add it. The macro below does this:

{
  "Name": "eval1",
  "CreationDate": "2023-9-4",
  "Commands": [
    {
      "Command": "store",
      "Target": "123+123",
      "Value": "ocrresult",
      "Description": ""
    },
    {
      "Command": "executeScript_Sandbox",
      "Target": "return ${ocrresult}.split(\"+\")[0].trim();",
      "Value": "First_Part",
      "Description": ""
    },
    {
      "Command": "echo",
      "Target": "${First_Part}",
      "Value": "",
      "Description": ""
    },
    {
      "Command": "executeScript_Sandbox",
      "Target": "return ${ocrresult}.split(\"+\")[1].trim();",
      "Value": "Second_Part",
      "Description": ""
    },
    {
      "Command": "echo",
      "Target": "${Second_Part}",
      "Value": "",
      "Description": ""
    },
    {
      "Command": "executeScript_Sandbox",
      "Target": "return parseInt(${First_part})+parseInt(${Second_part})",
      "Value": "a",
      "Description": ""
    },
    {
      "Command": "echo",
      "Target": "${a}",
      "Value": "",
      "Description": ""
    }
  ]
}