This example will change the item name for the data response object

add_filter( 'rest_prepare_frm_entries', 'change_item_name', 10, 3 );
function change_item_name( $response, $item, $request ) {
    if ( isset( $response->data['name'] ) ) {
        $response->data['name'] = 'place here the new name of the item';
    }
    return $response;
}

This example will change the field name for the data response object.

add_filter( 'rest_prepare_frm_fields', 'change_field_name', 10, 3 );
function change_field_name( $response, $field, $request ) {
    if ( isset( $response->data['name'] ) ) {
        $response->data['name'] = 'place here the new name of the field';
    }
    return $response;
}

This example will change the form name for the data response object.

add_filter( 'rest_prepare_frm_forms', 'change_form_name', 10, 3 );
function change_form_name( $response, $form, $request ) {
    if ( isset( $response->data['name'] ) ) {
        $response->data['name'] = 'place here the new name of the form';
    }
    return $response;
}

This example will allow you to convert a specific meta key to an integer.

add_filter( 'rest_prepare_frm_entries', 'my_custom_function' );
function my_custom_function( $response ) {
	$meta_key = '5a4m0'; // change this to the meta key that needs to be converted to an integer.
	
	if ( isset( $response->data ) && ! empty( $response->data['meta'] ) && isset( $response->data['meta'][ $meta_key ] ) ) {
		$response->data['meta'][ $meta_key ] = (int) $response->data['meta'][ $meta_key ];
	}

	return $response;
}