Wa alaikum assalam! I'm sorry to hear that you are facing difficulties with the YouTube to MP3 or MP4 converter sites. These sites often face issues due to copyright concerns and changes in YouTube's policies. It is important to use such tools cautiously, as they may violate YouTube's terms of service.
If you are looking to download YouTube videos or audio for personal use, you can consider using official methods provided by YouTube itself. YouTube Premium offers the ability to download videos for offline viewing on mobile devices. This is a legitimate way to access content offline without violating any terms of service.
Alternatively, there are other platforms like YouTube Music and YouTube TV that offer offline access to music and videos respectively, within their subscription plans.
If you still prefer to use third-party converters, be sure to research and choose reputable sites that are known for being safe and reliable. Always exercise caution when downloading content from the internet to protect your device and personal information.