As title, Am I allowed to use dsfix? because I have a weak computer, I need dsfix to reduce the game resolution. According to ds speed run rule: "You may not make any modifications to the game that affect the gameplay itself. This includes DSFix's popular framerate unlock feature which has to be completely turned off. Unlocking the framerate and setting it to 30 FPS within the DSFix config file will still cause discrepancies as to how the game runs and is therefore also banned." so as long as i don't use framerate unlock feature can i still use dsfix?

That is correct, yes. The FPS feature has to be completely turned off, then you are fine!

Okay. I will show my dsfix.ini file at the beginning of the video to make sure that fps unlock is off

You do not need to do that, it would be quite obvious if the unlocker was enabled.