Forminator: how to create hidden hash field

Hi,

My site is using Forminator.
I need to calculate the hash of another field {text-1} as a new field that will be saved. I looked into calculation fields, but they only accept numerical values, and won’t have the hash256 I need.
I tried creating my own Forminator Add-On, adding a filter (inspired from this post https://wordpress.org/support/topic/how-to-get-wordpress-post-id-from-forminator-form-not-page-id/) to override the value of my new field {calculation-1} with the correct php calculation, but it’s not working.
See code below.

Is there a document that explains the flow of forminator ?

add_filter( 
	'forminator_bqeth_form_override_hash', 
	function( $submit_errors, $form_id, $field_data_array ) {
		$text1 = '';
		var_dump($field_data_array);
		foreach( $field_data_array as $field ) {
			if ( ! isset( $field[ 'name' ] ) ||  ! isset( $field[ 'value' ] )|| $isbn_field !== $field[ 'name' ] ) {
				continue;
			}
			if ( isset( $field[ 'name' ] ) && $field['name'] == 'text-1') {
				$text1 = $field['value'];
			}
		}
		foreach( $field_data_array as $field ) {
			if ( ! isset( $field[ 'name' ] ) ||  ! isset( $field[ 'value' ] )|| $isbn_field !== $field[ 'name' ] ) {
				continue;
			}
			if ( isset( $field[ 'name' ] ) && $field['name'] == 'calculation-1') {
				$field['value'] = hash('sha256', $text1, true);
			}
		}
		return $submit_errors;
	}, 
	20, 3 
);

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