“No matter what” is similar to “whatever happens”, or “regardless”.
- No matter what, I will always love my children.
- He can’t make her happy no matter what he does.
- I won’t give up no matter what!
Here’s more explanation on Culips.com. You can listen to the audio, and also read the transcript, with a little quiz.
And – you can watch many examples of “no matter what” used in sentences on YouGlish.com.