To trigger a form post request using JavaScript, you can use the submit() method on the form element. Here's an example:

// Get the form element
var form = document.getElementById('myForm');

// Trigger the form submission
form.submit();

This will submit the form using the POST method. If you want to specify a different method, such as GET, you can set the method attribute of the form element before calling the submit() method. Here's an example:

// Get the form element
var form = document.getElementById('myForm');

// Set the form submission method to GET
form.method = 'GET';

// Trigger the form submission
form.submit();

Keep in mind that this will only work if the form has a submit button. If the form does not have a submit button, you can trigger the form submission by calling the submit() method on the form object in response to a user action, such as a button click or a key press. For example:

// Get the form element
var form = document.getElementById('myForm');

// Get the button element
var button = document.getElementById('myButton');

// Add an event listener for the click event
button.addEventListener('click', function() {
  // Trigger the form submission
  form.submit();
});

This will create a submit button and add it to the form, and then click the button to trigger the form submission.

I hope this helps!