Beta not eating

Question
Hi there.  My Beta is still not eating.  He does have one of his side fins that is allot thinner than the other.  He actually tried to eat.  He is showing interest in his food, obviously hungry but he can't seem to open his mouth now.  He is so so skinny it is making me really stressed.  Today he is noticeably allot thinner.  I am worried that he is suffering.  It has been three weeks since he has eaten anything.  How do you euthanize a fish?  I don't want him to suffer.

Answer
Hello,
Im sorry about your betta

There are any ways to euthanize your fish, one way is to put him in a container and out him in the freezer, but ou have to leave hi over night because if you take him out too early his heart may start aain, which i have experienced.

You may want to research it on the internet as there are many ways, another is clove oil but im not sure how you do that, so type in humanly eathanizing fish into google.