Problems with toner transfer method
If you heat the toner it will melt. Take the printed paper and put it on an iron for clothes, see if it melts.
There is another method, use acetone mixed with isopropyl alcohol. It requires no heating. But the acetone must be pure, not mixed with water.
It is very important to heat and press it uniformly(heat), or press it uniformly(acetone method). Use warm water to remove the paper. Let the water completely soak the paper.