How to use bootstrap drapdown along with text box and a submit button to post data - django-templates

Question

This is what I want to achieve this in django/bootstrap.
The user is supposed to select options from two DDLs and enter a number in the box, then press update to post parameters to server.
But it does not work.
And below is the code I have written:
(I have removed some django lines - but there will be loops and variables to get data from the form)
<form class="form-inline " method="post" action="{% url 'historical' %}">
<div class="dropdown">
<button class="btn btn-secondary dropdown-toggle" type="button" id="dropdownCrypto"
name="crypto" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
{{Selected-Coin}}
</button>
<div class="dropdown-menu" aria-labelledby="dropdownCrypto">
<a class="dropdown-item">BTC</a>
<a class="dropdown-item">XRP</a>
</div>
</div>
<div class="dropdown">
<button class="btn btn-outline-secondary dropdown-toggle" type="button"
id="dropdownCurrency" data-toggle="dropdown" aria-haspopup="true"
aria-expanded="false">
{{Selected-Currency}}
</button>
<div class="dropdown-menu" aria-labelledby="dropdownCurrency" name="currency">
<a class="dropdown-item" href="#USD">USD</a>
<a class="dropdown-item" href="#EUR">EUR</a>
</div>
</div>
<input class="form-control " type="number" aria-label="Period"
name="period" value="10"> days
<button class="btn btn-outline-secondary " type="submit">Update</button>
</form>