Dependency Wrong in 2019 for stimulus refund. Parents were listed as dependents.

 

When filing my grandsons taxes for 2019 I indicated he was being claimed by his parents, however this was wrong, as a result he didn't get a stimulus refund for 2019. What do I have to do to get 2019 refund and 2020 refund? Can I file an amended return for 2019 and wait some number of weeks and then file 2020 taxes where the stimulus refund can gotten back?

Also, if I file an amended return can it be e-filed in Turbo Tax, since the IRS now accepts e-filed amended returns? Does Turbo Tax support this?