Change the currency symbol or remove it in the inputmask currency

You can change the symbol by using the prefix option. Below is a snippet where I do this in two different ways, modifying the currency alias and defining my own alias.

In your version you couldn't type anything since the mask property is used to restrict input and setting it to 0.00 only allows those four characters to be entered and nothing else. A mask of 9.99 would allow a number followed by a period and two numbers. 9 has a special masking definition allowing any number.

Inputmask.extendAliases({
  pesos: {
            prefix: "₱ ",
            groupSeparator: ".",
            alias: "numeric",
            placeholder: "0",
            autoGroup: true,
            digits: 2,
            digitsOptional: false,
            clearMaskOnLostFocus: false
        }
});

$(document).ready(function(){
  
  $("#currency1").inputmask({ alias : "currency", prefix: '' });
  $("#currency2").inputmask({ alias : "currency", prefix: '₱ ' });
  $("#currency3").inputmask({ alias : "pesos" });

  
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery.inputmask/3.2.6/jquery.inputmask.bundle.min.js"></script>

<label>REMOVE CURRENCY SYMBOL</label><br>
<input type="text" id="currency1" /><br>

<label>CHANGE THE CURRENCY SYMBOL</label><br>
<input type="text" id="currency2" /><br>

<label>CHANGE THE CURRENCY SYMBOL, using an alias</label><br>
<input type="text" id="currency3" />


Solution with data-inputmask attribute

$(document).ready(function(){
  $("input").inputmask();
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery.inputmask/3.2.6/jquery.inputmask.bundle.min.js"></script>

<label>REMOVE CURRENCY SYMBOL</label><br>
<input type="text" id="currency1" data-inputmask="'alias': 'decimal', 'groupSeparator': ',', 'autoGroup': true, 'digits': 2, 'digitsOptional': false, 'placeholder': '0'" style="text-align: right;"><br>
<label>CHANGE THE CURRENCY SYMBOL</label><br>
<input type="text" id="currency2" data-inputmask="'alias': 'decimal', 'groupSeparator': ',', 'autoGroup': true, 'digits': 2, 'digitsOptional': false, 'prefix': '₱ ', 'placeholder': '0'" style="text-align: right;">