The embassy in Vientiane and the official consulate in Savannakhet will issue a non-o visa for retirement.
You could also leave and re-enter the country to get a 30 day visa exempt entry and the apply for the non-o visa at immigration. See: https://www.immigration.go.th/wp-content/uploads/2022/02/9.FOR-RETIREMENT-PURPOSES-50-YEARS-OLD-NON-O.pdf
If you have a re-entry permit you would have to wait until the day it expires to leave and re-enter the country,