If you wanted to see the "Good Ending" with Character A, but you were currently on the "Bad Ending" path with Character B, your only option was the "Nuclear Option": delete your save file and start from the beginning.
The Ultimate Guide to Ren'Py Save Editors: How to Modify Your Visual Novel Saves renpy save editor
# Modify a variable save_data['player_health'] = 100 If you wanted to see the "Good Ending"
Ren’Py games store save files in different locations depending on the operating system and how the game was built. Instead of replaying, you edit the flag
You chose the wrong dialogue option 5 hours ago, and now you're locked out of the true ending. Instead of replaying, you edit the flag.
Several websites offer browser-based save editors. : Uploading your save file to an unknown server risks exposing your data (or worse, injecting malware). Use only if you trust the source and the game is single-player offline.