Your softener kit comes with a bypass valve. It looks like a plastic cube with knobs. You’ll attach it to the inlet and outlet ports on the back of the unit.
Make sure the arrows on the valve match the water flow direction. Water goes in the “in” side and comes out the “out” side. It’s not rocket science, but it is water science.
Secure it with those little clips included in the box. If you lose them, you’ll be improvising with zip ties. Zip ties work, but they look sad.