Developers are recommended to have (by default) both a mainnet and devnet/testnet version with a toggle to test the protocol on both, as there may be differences in performance that are useful to be able to test:
It is useful to have a devnet or testnet version, and also a mainnet version for full testing
Authenticating Transactions
If you need to authenticate transactions, the recommended course of action is to use the SPL wallet adapter, which is what e.g. sollet.io users to connect to DEXes.