encodedOffset deprecation

yourString1.yourIndex.utf16Offset(in: yourString2)

A simple and correct way to create an NSRange from a Range<String.Index> is to use its initializer:

public init<R, S>(_ region: R, in target: S) where R : RangeExpression, S : StringProtocol, R.Bound == String.Index

In your case:

if let range = text.range(of: host) {
    return NSRange(range, in: text)
}