Saving text to a txt file on a html server?

Im building a small website and ive run into a problem i want to save a number that is hardcoded to a .txt file on the press of a button.

Ive already tried some examples online from other website but the only time i could same smthing was when i use php and it wasnt on a button press

                ...
                <br>
                <br><table id="tblCustomers" style="width: 100%;">
                    <tr>
                        <td style="width: 50%;">
                        <button onclick="location.href='{% url 'script' 
                         %}'">Execute Script</button> <hr>
                             //On this button it should save a 23 to a txt 
                               file wich is in the same folder and has the 
                               name contacts.txt                 
                        </td>
                        <td style="width: 50%;"><input type="button" 
                         id="btnread" value="Count Rows" /></td>
                    </tr>
                </table>
                ...

this is something else i tried it doesnt work ether.