Hello, who has an Avent bottle, can you tell me how you determine ml? …

Hello, who has an Avent bottle, can you tell me how you determine ml? We had an old regular one, there were 30, 60, 90, on 30ml one teaspoon. And here I don't understand where to measure to check. By the way, everyone praised Avent so much that I couldn't hold back and bought one too)))