如何从表单中选择一个操作页面，然后将值提交到该页面HTML，PHP，Javascript

I'm trying to create a page with <form>, <option> and <select> attributes in a php page where I can select an action page from a dropdown menu. Like this Linking to other pages in HTML via drop-down menu And then depending on the option selected ask the user to input a text and be able to submit that reason to that action page. Similar to this Add input-box when selecting a specific option into select drop down

Also please post how you would submit the values to the action page in the way you have your code setup as currently I have been following this method. https://stackoverflow.com/a/1977439/9010400

Example of my form submission which doesn't have the action page selection.

If the below form action page is selected then post the values to that page, but I would like it to ask for a text input for the "reason" before posting.

<form action="url/page.php" method="POST"> <input type="hidden" name="user" value="tester" /> <input type="hidden" name="reason" value="test" /> <input type="submit" value="Ok"/>

In a way I'm trying to combine those different questions/answers I have mentioned in this post. I hope I have been clear as to what I trying to ask for help. Any help is much appreciated. Thank you.

Edit: Some more info: I want to able to post values to the form action I select. For example: Change form action on select option But I would also like to add a user input option and then submit that value as well to the action form.

Try this. It will look for the form which name matches the selected option value and show it. Every other form will be hidden.

function showSelectedForm(){
  var selected_form = document.querySelector('select').value
  var forms = document.querySelectorAll('form')
  for(var i=0;i<forms.length;i++){
    if(forms[i].getAttribute('name')==selected_form)
      forms[i].style.display = 'block'
    else
      forms[i].style.display = 'none'
  }
}

form{
  margin-top: 25px;
  display: none;
}
form label{
  display: block;
}

Action:
<select onchange="showSelectedForm()">
  <option disabled selected>Please choose</option>
  <option value="change_name">Change Name</option>
  <option value="report_user">Report User</option>
  <option value="delete_account">Delete Account</option>
</select>

<form name="change_name" action="/php/change_name.php">
  <label>Name <input type="text" name="name"></label>
  <label>Reason <input type="text" name="reason"></label>
  <input type="submit">
</form>

<form name="report_user" action="/php/report_user.php">
  <label>User <input type="text" name="user"></label>
  <label>Report <textarea name="report"></textarea></label>
  <input type="submit">
</form>

<form name="delete_account" action="/php/delete_account.php">
  <label>Name <input type="text" name="name"></label>
  <label>Are you sure? <input type="checkbox"></label>
  <input type="submit">
</form>

</div>