how can download webapge as .html/.png after i inputed text in text box below is my code

how can download webapge as .html/.png after i inputed text in text box below is my code

<div class="container">
<form>
    <div class="form-group">
        <label for="link">Paste Website Link Below</label>
        <input type="link" class="form-control" id="download" placeholder="Enter website link" >
      <br>
    <butt class="btn btn-primary">Download </button>

</form></div>

i know this thing works for downloading webpage or any file but want when we type link their and then download help