Purpose of iOS Team ID in advanced settings

Why should I give our iOS Team Id in Client’s Advanced settings ? Is it for any security ? How can I publicly give our team ID to you ?

It is used to include that client application in the apple-app-site-association file that is served at https://{your_domain}.auth0.com/apple-app-site-association. This is a requirement (by Apple) when using universal links so you can skip it otherwise.