Question
I cannot easily insert the paper. How do I insert the paper properly?
Answer
It is not easy to insert the paper to STP-131. Try the method shown in the following picture and the paper insertion should be easier. 
It is not easy to insert the paper to STP-131, and the possibility of paper jam is higher than other models as the paper may be shifted in one direction during insertion.
As the sensor is located on the right side, fold the paper as shown in the picture and insert the paper. Then the paper touches the sensor gently and it will be inserted smoothly.