I cannot transfer songs to my iPhone

I really need some help from anyone who knows how to fix this issue.

So, whenever I sync my iPhone and turn on iTunes, I definitely had more options than it shows on the picture below.

But as you can see, I don't have all the "transfer songs" or "sync music" kind of options that I used to have.

So neither can I transfer new songs into my iPhone nor can I manage the previous songs I had in my iPhone,

I would really appreciate if someone could help me.

Thank you!