Transaction underpriced on Metamask?

I'm trying to burn one of my ERC721 tokens in my deployed contract but as you can see from my image the transaction fails with that error even if I did not touch anything when metamask prompts me to sign the transaction.

What's going on?

Well, if Metamask is invoked on Etherscan, the default setting on the popped up window is actually not working, usually setting the gas fee too low. The solution is to choose one of the three options Low, Medium and High on top. This would update the gas fee to reflect the real-time network condition.