function doPost(e) {
  const args = getget(JSON.parse(e.postData.contents)));
...

}

const varsDict = {
  chatType: "$..message.from.chat.type",
  callback_query_id: "$..callback_query.id",
  callback_query_from_id: "$..callback_query.from.id"
}


function getget(e) {
  let t = {}
  for (x in varsDict) {
    let value = jsonPath(e, varsDict[x])[0];
    value ? t[x] = value : delete t[x];
  }
  return t;
}

function jsonPath(obj, expr, arg) {
  var P = {
    resultType: arg && arg.resultType || "VALUE",
    result: [],
    normalize: function (expr) {
      var subx = [];
      return expr.replace(/[\['](\??\(.*?\))[\]']/g, function ($0, $1) { return "[#" + (subx.push($1) - 1) + "]"; })
        .replace(/'?\.'?|\['?/g, ";")
        .replace(/;;;|;;/g, ";..;")
        .replace(/;$|'?\]|'$/g, "")
        .replace(/#([0-9]+)/g, function ($0, $1) { return subx[$1]; });
    },
    asPath: function (path) {
      var x = path.split(";"), p = "$";
      for (var i = 1, n = x.length; i < n; i++)
        p += /^[0-9*]+$/.test(x[i]) ? ("[" + x[i] + "]") : ("['" + x[i] + "']");
      return p;
    },
    store: function (p, v) {
      if (p) P.result[P.result.length] = P.resultType == "PATH" ? P.asPath(p) : v;
      return !!p;
    },
    trace: function (expr, val, path) {
      if (expr) {
        var x = expr.split(";"), loc = x.shift();
        x = x.join(";");
        if (val && val.hasOwnProperty(loc))
          P.trace(x, val[loc], path + ";" + loc);
        else if (loc === "*")
          P.walk(loc, x, val, path, function (m, l, x, v, p) { P.trace(m + ";" + x, v, p); });
        else if (loc === "..") {
          P.trace(x, val, path);
          P.walk(loc, x, val, path, function (m, l, x, v, p) { typeof v[m] === "object" && P.trace("..;" + x, v[m], p + ";" + m); });
        }
        else if (/,/.test(loc)) { // [name1,name2,...]
          for (var s = loc.split(/'?,'?/), i = 0, n = s.length; i < n; i++)
            P.trace(s[i] + ";" + x, val, path);
        }
        else if (/^\(.*?\)$/.test(loc)) // [(expr)]
          P.trace(P.eval(loc, val, path.substr(path.lastIndexOf(";") + 1)) + ";" + x, val, path);
        else if (/^\?\(.*?\)$/.test(loc)) // [?(expr)]
          P.walk(loc, x, val, path, function (m, l, x, v, p) { if (P.eval(l.replace(/^\?\((.*?)\)$/, "$1"), v[m], m)) P.trace(m + ";" + x, v, p); });
        else if (/^(-?[0-9]*):(-?[0-9]*):?([0-9]*)$/.test(loc)) // [start:end:step]  phyton slice syntax
          P.slice(loc, x, val, path);
      }
      else
        P.store(path, val);
    },
    walk: function (loc, expr, val, path, f) {
      if (val instanceof Array) {
        for (var i = 0, n = val.length; i < n; i++)
          if (i in val)
            f(i, loc, expr, val, path);
      }
      else if (typeof val === "object") {
        for (var m in val)
          if (val.hasOwnProperty(m))
            f(m, loc, expr, val, path);
      }
    },
    slice: function (loc, expr, val, path) {
      if (val instanceof Array) {
        var len = val.length, start = 0, end = len, step = 1;
        loc.replace(/^(-?[0-9]*):(-?[0-9]*):?(-?[0-9]*)$/g, function ($0, $1, $2, $3) { start = parseInt($1 || start); end = parseInt($2 || end); step = parseInt($3 || step); });
        start = (start < 0) ? Math.max(0, start + len) : Math.min(len, start);
        end = (end < 0) ? Math.max(0, end + len) : Math.min(len, end);
        for (var i = start; i < end; i += step)
          P.trace(i + ";" + expr, val, path);
      }
    },
    eval: function (x, _v, _vname) {
      try { return $ && _v && eval(x.replace(/@/g, "_v")); }
      catch (e) { throw new SyntaxError("jsonPath: " + e.message + ": " + x.replace(/@/g, "_v").replace(/\^/g, "_a")); }
    }
  };

  var $ = obj;
  if (expr && obj && (P.resultType == "VALUE" || P.resultType == "PATH")) {
    P.trace(P.normalize(expr).replace(/^\$;/, ""), obj, "$");
    return P.result.length ? P.result : false;
  }
}