This is a modified version of the filament guide I found here: https://www.thingiverse.com/thing:4665850

The original one was off a bit and was creating tension before entering the extruder. I have moved it over a few mm to the right place and now it works great. I would also like to add my extruder is an upgraded Creality metal extruder for reference. You might want to check to see if the old or the new one will work for you.

Update: Uploaded final version the old one was slightly too low.