Why doesn't font awesome show up in the modal?

Question

HTML

I am seeing this problem. I set the datepicker in the field that is in the modal window. But the awesome arrows that switch months are not displayed. If I install it not in a modal, but let's just say on a site page, then everything is displayed, but in the modal it seems like it just doesn't see the font. What could be the matter or how to make it see in the modal window?
https://prnt.sc/hg573o
An example is here: https://tempusdominus.github.io/bootstrap-4/Usage/

Answer 1

You have display:none in template.css;

.input-item .fa {
    position: relative;
    right: 7px;
    display: none;
    top: 6px;
    font-size: 18px;
}

can be treated like this

.bootstrap-datetimepicker-widget .fa{
    display:inline-block;
}

or another selector to taste)