User-agent: *
User-agent: Googlebot
User-agent: AdIdxBot
User-agent: BingPreview
Disallow: /app/

User-agent: SMTBot
Disallow: /
User-agent: AhrefsBot 
Disallow: /
User-agent: YandexBot
Disallow: /
User-agent: SemrushBot
Disallow: /