When Jesus and his disciples arrived in Capernaum the people collecting the temple tax came to Peter and asked:
Doesn’t the teacher pay the temple tax?
When they came into the house where they were staying, Jesus asked Peter:
What do you think, Simon? Who do the kings of the Earth receive their tax, toll or tribute from? From their sons or from strangers?
So the sons are free. But in order not to cause them to stumble, go to the sea and cast a line with a hook on it, and then open the mouth of the first fish you catch.
In it you will find enough to pay the temple tax. Take it and give it to those who are collecting the tax.