Calmly and cooperatively wearing a muzzle is an important life skill for dogs. It can be super positive to train too! So get the treats ready and let the training begin. You can even start with a paper cup so your dog gets used to putting his or her nose inside. Easy peasy!
Training dogs to wear a muzzle is important so they become accustomed to it and will accept it readily when needed or advised for a specific purpose. It's much better if wearing a muzzle can be introduced in a fun way rather than waiting until a situation in which they may already be suffering from fear, anxiety and stress.
It's a good idea to break the training down into easy stages and work on each stage until your dog is completely comfortable. Suggested stages:
1. putting their nose into the muzzle voluntarily
2. laying the strap over their neck
3. doing the strap up
4. building up duration
You may never need to use a muzzle but the right time to introduce it is well before it may be needed! Have fun muzzle training :)