MetaMask Swaps only collates potential swaps for tokens that have 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 checkcoingecko.com, search for your token, then click the Markets tab to see where you could swap this token and where it can be traded.