Text her and always reply "hmm". What does this mean? Don't like it? I just wanted to give her a pair of shoes and said no. I used to give my favorite gifts.

Unless she has a quirk, she just doesn't have enough interest in you, and probably just wants to get your things for free, but you should know that only people close to her will give them shoes, which probably means that she doesn't want to have closer progress with you.

But if you still want to improve your relationship with her, try to find out why she always communicates with you in this way. Specifically, it can be euphemistic.

"You're so cute, you answer like you're being criticized."

But if he always answers you gracefully,

I suggest you keep friendship with her.