Every toilet gets blocked every now and then and the most common causes are too much material in the pan and low water pressure that cannot move it.
Additives can be used to unblock a sink but as products often create heat this is not advised for a toilet.
The best approach is to unblock the toilet using mechanical means.
If the toilet bowl is empty Add water so it covers the plunger.
Add some washing up liquid to the toilet water.
Push the plunger right down to the toilet trap and position the rubber to form a seal.
Pull the plunger so it sucks the material out.
Continue with this method and repeat quickly and forcefully to force the water into the toilet and push through the blockage.
Wear rubber gloves and leave a bucket by the toilet.
Extend the handle of the auger.
Push the auger until you feel resistance, which will be from the blockage.
Crank on the handle so it rotates to break up the clog.
Extend the handle and remove from the bowel.
Remove the excess material to the bucket.
Watch for the water draining down the toilet and repeat if necessary.
Once the blockage is cleared pour the material from the bucket back into the toilet.
A top tip is to use boiling water instead of cold water to cover the plunger.
A tight seal is the key to effective unblocking and if you have trouble forming a tight seal petroleum jelly can be applied to the part of the plunger that will be in contact with the toilet.