Placeholder on Select*

Hi there!

I can put placeholder in select field?

[select* chooseLetter include_blank “A” “B” “C” “D”]

Entitled Choose a letter “placeholder”

and not ” — ” when added include_blank the field?

I try
[select* chooseLetter “Choose a letter” “A” “B” “C” “D”] and
[select* chooseLetter placeholder “Choose a letter” “A” “B” “C” “D”]

but does work.

Can you help me?

https://wordpress.org/plugins/contact-form-7/