K-1 Availability and Tax Filing Question

Hi everyone,

I have an investment that provides me with a K-1 tax form. However, the firm managing the investment has informed me that the K-1 won't be available until September 2024.

My CPA advises waiting to file my tax return until I receive the K-1. On the other hand, I've seen discussions on online forums suggesting it's acceptable to file my return now and then submit an amendment later, once I have the K-1.

I'm unsure of the best course of action. Is there any official guidance from the IRS or any relevant tax authorities on handling situations like this?

Thanks in advance for your help!