How to open custom page from relation manager

I can open page from a resource row with an Action in

table->actions([Tables\Actions\Action::make('Stats')
    ->url(fn(Client $record): string =>  self::getUrl('stats-monthly', ['record' => $record]))

table->actions([Tables\Actions\Action::make('Stats')
    ->url(fn(Client $record): string =>  self::getUrl('stats-monthly', ['record' => $record]))

table->actions([Tables\Actions\Action::make('Stats')
    ->url(fn(Client $record): string =>  self::getUrl('stats-monthly', ['record' => $record]))

table->actions([Tables\Actions\Action::make('Stats')
    ->url(fn(Client $record): string =>  self::getUrl('stats-monthly', ['record' => $record]))

and

 public function getPages(): array
{
    return [
      'stats-monthly' => Pages\MonthlyStats::route('/{record}/monthly-stats'),

 public function getPages(): array
{
    return [
      'stats-monthly' => Pages\MonthlyStats::route('/{record}/monthly-stats'),

 public function getPages(): array
{
    return [
      'stats-monthly' => Pages\MonthlyStats::route('/{record}/monthly-stats'),

 public function getPages(): array
{
    return [
      'stats-monthly' => Pages\MonthlyStats::route('/{record}/monthly-stats'),

But how to do this in ResourceManager?
I want to open a Custom page from an action in in the InboxRelationManager which is on the Client.

->actions([
   Tables\Actions\Action::make('work')
   ->url(fn(CampaignContact $record): string =>  self::getUrl('work', ['record' => $record])),

->actions([
   Tables\Actions\Action::make('work')
   ->url(fn(CampaignContact $record): string =>  self::getUrl('work', ['record' => $record])),

->actions([
   Tables\Actions\Action::make('work')
   ->url(fn(CampaignContact $record): string =>  self::getUrl('work', ['record' => $record])),

->actions([
   Tables\Actions\Action::make('work')
   ->url(fn(CampaignContact $record): string =>  self::getUrl('work', ['record' => $record])),

and

public function getPages(): array
{
    return [
       'work' => ManageThread::route('/work'),

public function getPages(): array
{
    return [
       'work' => ManageThread::route('/work'),

public function getPages(): array
{
    return [
       'work' => ManageThread::route('/work'),

public function getPages(): array
{
    return [
       'work' => ManageThread::route('/work'),

. and I get error

\InboxRelationManager::getUrl does not exist

\InboxRelationManager::getUrl does not exist

\InboxRelationManager::getUrl does not exist

\InboxRelationManager::getUrl does not exist