Thanks for adding the specific error you received, hassangak212. 

As Fiat Lux - ASIA clarifying question, are you using QBOA Pakistan region, or do you mean you're located in Pakistan but using QBOA with a different region? Also, is your client book different from your region? It can be the reason why you got that particular error message.

While waiting for your response, please know that we can only accept clients in the same region. No worries, you can still work for a client in other countries.

You can let them invite you as the Company Administrator for you to access their file. You can share these steps with your clients to accomplish the process:

1. Go to the Gear icon.
2. Select Manage users.
3. Within the Users tab, then click Add user.
   
4. Select Company admin, then click Next.
5. Follow the on-screen instruction, then click Sa
    

Once done, you'll need to accept the invitation. This way, you can help them manage data from their QBO account. Feel free to check these resources for additional insights:

• Learn how to add, manage, or delete user profiles.
• User roles and access rights in QuickBooks Online.

You can always go back here and post your concerns about managing client's within your book. I'd be glad to help you. Take care and stay safe always.