How can you fix it?
Diagnosis will give you the clues to a solution.
When does it click - during a wash cycle - when spinning - when filling or pumping out - all the time before a programme is selected or only some of the time?
The frequency of the clicking will be another indication - does it click at the same interval or does the frequency of clicking change as perhaps the speed of the drum rotation varies?
Answers to these questions will help you to focus on what may be wrong with what - the likely cause.
Diagnosis comes first
Then you form a theory
Then you might test or confirm the theory
And last of all the fix and its verification
There's a contributor on here from New Zealand who is very knowledgeable about Appliances - he may be able to answer from his practical experience of clicking washers.
Alternatively you might call in an engineer.