I recently bought an iPhone and am compelled to convert main sim into an esim but I'm misunderstanding the process

Hi, so as you can see on the title, I just recently bought an iPhone 15. Since it has only one sim tray and I have 2 sim cards, I'd like to convert my main sim (Smart) into an esim so I could still use it. I have no plan on using a different number under Smart. However, I think I'm misunderstanding the process here. I just bought a ₱99 Smart esim and I thought they'd ask for my physical sim # but they didn't and instead gave me a new, different esim number.

Does this mean they aren't gonna convert my physical sim into an esim? If that's the case, how do I simply convert it? I really don't wanna be using a different Smart number because I've already registered my main sim to a lot of things and have been using it on essential stuff.

Thank you.