Fix gap under front door

The front door has a long triangle gap - like the shape of a shim, about a quarter inch high towards the opening side that tapers into flush.

I’ve tried dropping a bottom molding to be level with the doorframe, but then the door drags against the floor when it’s about 50% open.

I posted this previous and someone suggested automatic door bottom. This was the right answer, however I cannot seem to find one for the size of my door (35”, standard is 36”)

Anyone solved a similar issue? Thanks in advance