JavaScript in bookmarklet to open webpage and then select option from dropdown list on that webpage?

Question

I have written a JavaScript snippet for use as a bookmarklet in Firefox. It will open a webpage and then select an option from a dropdown menu and submit. It works as intended, except I have to click the bookmark twice, first opening the page, and then to select the option in the dropdown list. Is there a solution to do everything with just one click on the bookmark (perhaps by delaying execution)?

window.open("https://www.foreca.se/Sverige/Stockholm/Stockholm", '_self');

document.querySelector("#stationForm > select.stationSelect > option[value='1020002460']").selected = 'selected';
document.getElementById("stationForm").submit();

Answer 1

It seems it is not possible. The bookmarklet can only act on an already open web page according to this post.

However you can instead achieve the same with a userscript in for example Tampermonkey userscript manager.