Hi there, is there any way to use ton wallet (chrome extension ver) in testnet also? I could find it in web version (wallet.ton.org?testnet) but couldn't find it with chrome extension ver

I didn't know a chrome extension exists! Is it custodial or non-custodial?

may be non-custodial!

or any recommendation for a wallet that supports testnet "and" jetton?

NonCustodial, because you have access to your seed words

It's non-custodial if no one except you has your seed words. If they are being kept on some external server then it is custodial.

My recommendation is not to use testnet. You can deploy as many tokens as you want with the same details to mainnet. Just add suffix "-test5" to the token name.

You will do a maximum of 50 manual tests to see everything is working. This will set you back in fees approx $1. The time you will waste on setting up testnet is worth more :)