In order to sink putts, you must be lined up properly. Use alignment rods, when you practice.
Here’s how: find a 4 foot putt that is flat and straight, on your practice green. Lay two alignment rods down, parallel to one another and 4 inches apart. Position the rods so the hole is at one end. Place a golf ball at the other end, in between the alignment rods, four feet from the cup. Position a third alignment rod, perpendicular to the two alignment rods (and in between your stance), to indicate ball position in your stance. Play the golf ball slightly forward from the center of your stance. Position the putter head behind the golf ball and directly between the parallel lines of the alignment rods. Square your putter face to the hole. Practice putting over and over again, on this 4 foot straight putt with these alignment lines as visuals.
Repeating this drill is the key to proper alignment and sinking more putts.