Is there a cryptocurrency exchange where you can ‘upload’ your crypto?

Is there a cryptocurrency exchange where you can ‘upload’ your crypto?

Sorry if this question is more general to cryptocurrencies and not about bitcoins.
All of the Cryptocurrencies Exchange I know of only support popular cryptocurrencies (like Bitcoin, Ethereum, Litecoin…) and community requested ones (like Dogecoins or Putincoins), so my question is: Is there a Cryptocurrency Exchange where everyone could ‘upload’ (not a technical term) his own cryptocurrency and make it available to buyers and sellers, so not implemented just because it’s already famous/used? If this doesn’t exist, is it infeasible by some techincal means?
Thank you.