How to set the default font for text fields while making a pdf form?

Hello, I have been trying very hard to set a default font for the text fields that I put while making a pdf form. The font size and style works fine in the pdf form, but somehow when I try to fill up the pdf form, I can’t type in the default font which I had previously set.

Is there anything I’m doing wrong? Cause when I tried to fill up other pdf forms (made using other tools) I could enter texts in different fonts, but it isn’t working here.

Please have a look at:

Create a fillable form in Writer