His will indicates that he died 16 October 1822 at Sully sur Loire, Centre Val de Loire.
His will is available on The National Archives.
I read it that he
wrote this will on 16 October 1822, not died on that day.
Administration was then given on 7 March 1823 to William Morris his brother.
So he died sometime between these dates.
It does not look as if it was at Sully sur Loire.
The tables of births, marriages and deaths from January 1823 to January 1833 are on the archives-loiret site.
(I was going to post a link, but it's a huge string of letters and numbers - far too long to post on here. Sorry if you've already looked at this).
The site is
https://www.archives-loiret.frYou need to go to 'Etat civil et registres paroissiaux'
In the commune/paroisse box type 'Sully sur Mer', and '1823' in the date box.
The listing for the deaths from 1819 - 1828 are top of the list.
I've looked through the register.
He is not in it.
The 10 year tables for 1823 - 1833 are the 4th entry.
They start January 1823. His name is not listed.
I've checked the Hotel des Invalides archives page in case he was ever taken in there perhaps unwell after being a a Prisoner of War, but nothing comes up.
https://www.hoteldesinvalides.org/index.php?reset=1&onglet=0&langSorry not to have been more help.
Perhaps he came back to England and died there?
His 'good friends' who swear the writing and signature of the will of Apollos were from Charing Cross London.
By the way, I see his name is always written
Apollos in this document, not Appolos as you have written. He has actually signed 'Apollos Morris'.
Not that it would make a lot of difference when searching really.