Section 80DDB queries- most urgent

Hi,

So these queries are for someone who was diagnosed with a neurological disorder in F.Y.20-21, two months back. He had no health insurance. The cost of the hospitalization and the current treatment is huge. He falls in the 10% slab of ITR. Under section 80DDB exemption till 40k is allowed   

Few queries-

1. As per the above link form 10l is not required, this is it btw https://www.webtel.in/image/10I.pdf what documents/forms are required to be submitted while filing an itr?

2. If a person was hospitalized in an icu last month then can he get the above form plus bills etc. from the hospital in current date?

3. How exactly to take claim under this section while filing the return?

4. Any other heads up?

Thank You.