Sure try this:
Dear [Name],
My name is [Your Name] and I run the YouTube channel Symixstur. I am working on a video project and I was wondering if I might have permission to use [name of song] in my video.
If I am granted permission, please send me the appropriate links and paragraph that you would like me to place in the video description.
Please also let me know if you permit me to monetise the video, or whether you would prefer to make a content ID match on the video once published.
I look forward to hearing from you.
Kind regards,
[Your name]
I put a paragraph in there about adverts because they may not want you earning money from their video. The chances are, they will not want you to monetise and will make a content ID claim (not a strike, so not a problem) for the music. This is important, as if you monetise without permission they can launch a copyright claim against you.