First, make sure that you are using Node.js version of no less than 20.
Currently, this project is only tested for Synology DSM 7.1.1,you can try it. but I can't guarantee that it will work for your Synology NAS.
First you need to confirm that you can access across domains,for example in the React Native environment
First install the package globally
Then run cmd help message
run syno config -h
you will see the help message
add a connect configuration
then you can use it and exec command