Some people want to make their speaking voice sound more feminine as part of their gender expression. Other people do not. It is your choice. Those who do often start with voice practice.
There are three key parts to feminizing your voice:
Trans and gender diverse people who plan to take masculinizing hormones will often have their voice become lower in pitch from use of androgens like testosterone. It is possible to lower your pitch without taking hormones.
Generally speaking, you are trying to get your baseline pitch above 220 Hz to sound “masculine.”
Many transfeminine people use strategies that sound pinched or are in their falsetto, which is going to sound forced to other people.
Many transfeminine people retain a “masculine” inflection, including a monotone and poor diction. Slowing down, speaking more clearly, using more lilt, and using complete sentences will sound more “feminine” to other people.