How the selection box sets the properties of the display

Demo URL：https://anu-vue.netlify.app/guide/components/select.html#states

Through the case on the website, I want to achieve a custom display effect.

However, I found that I could not set the displayed elements manually

For example, in the above case, when I selected `VueJS`, I wanted to display `VueJS` instead of `vue` in the selection box