I got a script to remotely load js files, is there a way to make it retry\wait on errors?

If you want to check If script is loaded or not, you can do it by adding script.onload=function(){...} .

must note ‘- the script.onload must come before script.src

Your code, with onload function

loadScriptFromUrl = function(url) {
    var script = document.createElement('script');
    script.type = 'text/javascript';
    document.body.appendChild(script); 
    script.onload=()=>{
        console.log("script loaded")
        //whatever you want to do
    }
    script.async = false;
    script.src = url;
    script._url = url;

};

If you want to check for any error on loading you can go with script.onerror=function(){...}

It will also come before script.src

loadScriptFromUrl = function(url) {
    var script = document.createElement('script');
    script.type = 'text/javascript';
    document.body.appendChild(script); 
    script.onerror=()=>{
        console.log("script not loaded")
        //reload script like below
        loadScriptFromUrl(url);
        //or reload the whole window by location.reload() method
    }
    script.async = false;
    script.src = url;
    script._url = url;

};

If you want to wait until the function loads the script you can put this function under an async function, add await keyword before it and return a promise resolve under script.onload();

E.g.

async function parentFunct(){
loadScriptFromUrl =await function(url) {
  return new Promise((resolve,reject)=>{
    var script = document.createElement('script');
    script.type = 'text/javascript';
    document.body.appendChild(script); 
    script.onload=()=>{
        console.log("script loaded")
        resolve();
    }
    script.async = false;
    script.src = url;
    script._url = url;
  })
};
}

The above code will stop everything inside parentFunc() until the script is loaded Read more about js promises https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Asynchronous/Async_await