These may not be the southern green beans most think about, but when I lived in Florida these were a staple at southern dinners.
Turn on a multi-functional pressure cooker (such as Instant Pot®) and select Saute function. Add bacon to the hot pot and cook until browned, about 5 minutes. Add green beans and cook for 1 minute. Add water. Close and lock the lid. Select high pressure according to manufacturer's instructions; set timer for 4 minutes. Allow 10 minutes for pressure to build.
Release pressure carefully using the quick-release method according to manufacturer's instructions, about 5 minutes. Unlock and remove the lid. Transfer green beans to a serving dish and sprinkle with toasted pecans and pepper.