Hi there, I have recently started my bookkeeping business but I am not able to get invitation from client, the invitation is going to my mailbox not in my QBOA Bijender

If your client is using QBO CA and you have QBOA CA, make sure they invited you as Accountant not User.

Ensure your client going to Settings ⚙ and select Manage users.
Select Accounting firms.
Select Invite.
Complete the required fields and select Save.