Well this does not fix the page fully but it make it workable. Follow the steps.
Open fiverr.com, and click "inspect element". Go to "Console".
Then click on an asset (js/css) that has 403.
Now right click on it and click "open in new tab"
Enter the reCaptcha, you'll see the asset file now
Now repeat this for the assets that got 403
Now you got your page partially fixed, you might find some more JS missing, just go to console and fix that using the same way.
Open fiverr.com, and click "inspect element". Go to "Console".
Then click on an asset (js/css) that has 403.
Now right click on it and click "open in new tab"
Enter the reCaptcha, you'll see the asset file now
Now repeat this for the assets that got 403
Now you got your page partially fixed, you might find some more JS missing, just go to console and fix that using the same way.