One IRS web page, updated October 26, 2020, says:

“The following are also not eligible [for an Economic Impact Payment]: a deceased individual or an estate or trust.”

https://www.irs.gov/newsroom/economic-impact-payment-information-center-topic-a-eip-eligibility

But then the draft Form 1040 instructions for 2020 state:

“Generally, you are eligible to claim the recovery rebate credit . . .This includes someone who died in 2020, if you are preparing a return for that person.”

https://www.irs.gov/pub/irs-dft/i1040gi--dft.pdf