#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "\}\}\}(.*)"
Local $sString = "{"body":{"records": {"time": "2020-12-20T13:28:50.2164144Z","MachineGroup": "Windows 10", "Timestamp": "2020-12-20T13:27:18.6679858Z", "DeviceName": "3242d4e4.dc.democorp.com", "ReportId": 306737}}},"x-opt-sequence-number":159959006,"x-opt-offset":"2713650553292728","x-opt-enqueued-time":1624195823422}"
Local $sSubst = ""
Local $sResult = StringRegExpReplace($sString, $sRegex, $sSubst)
MsgBox($MB_SYSTEMMODAL, "Result", $sResult)
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for AutoIt, please visit: https://www.autoitscript.com/autoit3/docs/functions/StringRegExp.htm