According to the npm page you can use the following library in this way
npm install react-native-md5 --did you have to run it on your operating system console
import EventEmitter from "react-native-md5"; this is to import the library into your project
This would be an example how to use it
import md5 from "react-native-md5";
componentWillMount() {
let hex_md5v = md5.hex_md5( Date.now() +"" );
console.log(">>>>hex_md5:", hex_md5v);
let b64_md5v = md5.b64_md5( Date.now() +"" );
console.log(">>>>b64_md5:", b64_md5v);
let str_md5v = md5.str_md5( Date.now() +"" );
console.log(">>>>str_md5:", str_md5v);
let hex_hmac_md5v = md5.hex_hmac_md5("my_key", Date.now() +"" );
console.log(">>>>hex_hmac_md5:", hex_hmac_md5v);
let b64_hmac_md5v = md5.b64_hmac_md5("my_key", Date.now() +"" );
console.log(">>>>b64_hmac_md5:", b64_hmac_md5v);
let str_hmac_md5v = md5.str_hmac_md5("my_key", Date.now() +"" );
console.log(">>>>str_hmac_md5:", str_hmac_md5v);
}
the link where you can see it is link