Accountant was invited but she cant log in as she needs a password. Who gives theis PW?

Hi there, s-dutt.

To accept the client's invitation to view the company data, the accountant needs to use their QuickBooks Online login credential.

Please see this sample screenshot for reference: 

If they forgot their QuickBooks Online password, they can reset it by following the steps in this article: How do I reset my password for QuickBooks Online Accountant?.

For any additional questions or other concerns, please let me know and I'll get back to you the soonest. Stay safe.