MetaMask Swaps only displays quotes for potential swaps when there is sufficient liquidity on underlying markets. Generally, a few thousand dollars' worth of liquidity is required to mitigate price impact. Once a token has sufficient liquidity, it will be available.
The message ("error fetching quote") you see suggests that there is no liquidity available for the token you want to swap.
You can always check coingecko.com, search for your token, then click the Markets tab to see where you could swap this token and where it can be traded.