Set value JQUERY UI Slider with LeaFlet map

Question

im willing to modify the time value of the Leaflet TimeSlider plugin, i have this plugin that i modified so i can see in locale format.

https://github.com/carlosign/LeafletSlider-LocalTime/blob/master/src/SliderControl.js

Im willing to modify it with 2 textbox, one for the initial value and the other for the final value, the slider is a range one. I tried to set it with the classic jquery ui.

<input type="text" id="amount">
<input type="text" id="amount2">

and with JS

$("#amount").change(function() {
    $("#leaflet-slider").slider('values',0,$(this).val());
});
$("#amount2").change(function() {
    $("#leaflet-slider").slider('values',1,$(this).val());
});

But it doesnt work, the slider wont change its value.

Uncaught Error: cannot call methods on slider prior to initialization; attempted to call method 'option'

And the slider is initialized with the leaflet map. The inputs are not in the map div.