Use window.location.search:

var url = "https://exmaple.com";
var newurl = url + window.location.search;

newurl will contain all the get (ex. ?something=something&something2=something5) data.

To change the href of a:

var button = document.getElementById('#ptsBlock_553944');
button.href = button.href + window.location.search;

If you don't care about supporting older browsers you can use the URL API and URLSearchParams.

function appendCurrentUrlSearchParams(anchorElement) {
  const currUrlSearchParams = new URL(window.location.href).searchParams;
  const link = new URL(anchorElement.href);

  // uncomment this line if you want to clear query parameters already present in the anchor url
  // link.search = '';

  for (const entry of currUrlSearchParams.entries()) {
    link.searchParams.append(entry[ 0 ], entry[ 1 ]);
  }
  
  anchorElement.href = link.href;
}

Usage in your case:

appendCurrentUrlSearchParams(document.querySelector('#ptsBlock_553944 .ptsCell:nth-of-type(1) .ptsEditArea.ptsInputShell'));

Read Html select using select to change the link of a button with Javascript

specifically the section on

1. Get the element with something like document.getElement MDN getElement Link

2. Change the .href of that element to what you want.

function selectFunction() {
    var x = document.getElementById("selectopt").value;

    document.getElementById("mylink").innerHTML = x;
  
    document.getElementById("mylink").href = "http://www." + x + ".com";
  
}

document.location.pathname = '/questions/69240453/appending- 
current-url-parameters-onto-anchor-link/69240510';

//get the document pathname I chose from document.location
let data = document.location.pathname;

let preUrlString = 'www.example.com/form';

let newString = preUrlString + data;

console.log(newString);
'www.example.com/form/questions/69240453/appending- 
current-url-parameters-onto-anchor-link/69240510'

document.getElementById("mylink").href = newString;