Hey guys, how can I get fee from msg.value?

I want to get 1/20 from any transaction from contract to owner address and 19/20 to _to

Declare a local variable and define it as 1/20th of the value the send it to the appropriate address. Then send value - tax to _to

Also, mb you knwo some Gravatar alternatives in web3 World? Just ot get some userpic binded to Wallet Address? Could be NFT or smth else

identicon
blockies
jazzicons

here's metamasks
https://github.com/MetaMask/metamask-extension/blob/develop/ui/components/ui/identicon/blockieIdenticon/blockieIdenticon.component.js#L5