Referencing a paragraph-type via code

I'm new to Drupal so the following may not be accurate.

I want to reference a paragraph-type from an Entity reference revisions field created in a content type using a hook_form_alter and I can't find the way to do so.

I've created a content type using the UI and also a new Entity reference revisions field inside it without selecting a paragraph. I need to select it by code (and even more than just one).

Also I need the paragraph(s) to be opened in the form for editing.

Can someone please send a working example for that?

Ways I've tried so far:

1.

$form['my_paragraph_field'] = [
  '#type' => 'entity_reference_revisions',
  '#entity_type' => 'paragraph',
  '#entity' => $paragraph,
  '#bundle' => $paragraph_type->id(),
  '#cardinality' => 1,
  '#title' => 'Paragraph',
  '#default_value' => $paragraph,
  '#weight' => 10,
  '#element_validate' => [],
  '#process' => []
];

  $p = ParagraphsType::load('test_paragraph');

  $id = $p->id();

  $paragraphs = ParagraphsType::loadMultiple([$id]); // Load entities 
  $form['my_paragraph_field']['widget'][0]['#entity'] = $paragraphs;

$form['field_test_paragraph']['#selection_settings']['target_bundles'] = ['test_paragraph', 'bundle_2'];

$node = $form_state->getFormObject()->getEntity();
$storage = \Drupal::entityTypeManager()->getStorage('paragraph');
$node->set('field_test_paragraph',  [
  'target_id' => $id,
  'target_revision_id' => $storage->getLatestRevisionId($id),
]);

If the question is not clear enough, please tell me what is missing.

Thanks!