Which inner tube do I need to buy for 28 inch fixie bike?
All you need to know the wheel rim diameter, tire width, valve type and valve length.

Google translate to English of what's written on you tire is:


  Tire front Brand: Kenda Type: K-193 Size: 28 inches Tire width: 28 mm 


28 inches refers to the wheel diameter. This means a rim with a rim tire bead seat diameter of 622mm, also known as 700c (and 29 inches for mountain bikes).

Tire width: 28 mm means, well, the tire is 28mm wide. Typically tubes have a minimum and maximum tire width they will support.

See here and here for determining what valve type you have.

You need valves long enough to reach through the rim with at least a couple of centimeters protruding.